Factorise.
x2 + 9x + 18
On comparing with standard quadratic equation that is
we have,
a = 1, b = 9 and c = 18
Now here,
Product ac = 118 = 18
Factors of 18; 29 and 63
Sum should be b = + 9
From above factors (+ 6x + 3x)
will give + 9x sum
therefore + 9x is replaced by ( + 6x + 3x)
Now above eq. becomes
x2 + 6x + 3x + 18
⇒ ; taking x common
⇒ (x + 3)(x + 6)
Factorise.
x2 – 10x + 9
On comparing with standard quadratic equation that is
we have,0
a = 1, b = – 10 and c = 9
Now here,
Product ac = 19 = 9
Factors of 9; 19 and 33
Sum should be b = – 10
From above factors ( – 1x – 9x)
will give – 10x sum
therefore – 10x is replaced by ( – 1x – 9x)
Now above eq. becomes
; taking x and – 9 common
(x – 1)(x – 9)
Factorise.
y2 + 24y + 144
On comparing with standard quadratic equation that is
we have,
a = 1, b = + 24 and c = + 144
Now here,
Product a × c = 1 × 144 = 144
Factors of 144; 12 × 12; 24 × 6;144 × 1;
48 × 3; 72 × 2
Sum should be b = 24
From above factors (12y + 12y)
will give + 24y sum
therefore + 24 is replaced by ( + 12y + 12y)
Now above eq. becomes
; taking y and + 12 common
(y + 1)(y + 12)
Note: Try to find all factors of “c”, then choose from it that combination whose sum or difference give “b”
Factorise.
5y2 + 5y – 10
On comparing with standard quadratic equation that is
we have,
a = 5, b = + 5 and c = – 10
Now here,
Product a × c = 5 × – 10 = – 50
Factors of 50; 5 × 10; 25 × 2;50 × 1
Sum should be b = + 5
From above factors ( – 5y + 10y)
will give + 5y sum
therefore + 5y is replaced by ( – 5y + 10y)
Now above eq. becomes
; taking 5y and + 10 common
(y – 1)(5y + 10)
5(y – 1)(y + 2); 5 common
Note: if given equation’s constant a,b,c have common multiple take it out and then factorize.
Factorise.
p2 – 2p – 35
On comparing with standard quadratic equation that is
we have,
a = 1, b = – 2 and c = – 35
Now here,
Product a × c = 1 × – 35 = – 35
Factors of 35; 1 × 35 and 7 × 5
Sum should be b = – 2
From above factors ( – 7p + 5p)
will give – 2p sum
therefore – 2p is replaced by ( – 7p + 5p)
Now above eq. becomes
; taking p and + 5 common
(p – 7)(p + 5)
Factorise.
p2 – 7p – 44
On comparing with standard quadratic equation that is
we have,
a = 1, b = – 7 and c = – 44
Now here,
Product a × c = 1 × – 44 = – 44
Factors of 44; 1 × 44; 2 × 22;4 × 11
Sum should be b = – 7
From above factors ( – 11p + 4p)
will give – 7p sum
therefore – 7p is replaced by ( – 11p + 4p)
Now above eq. becomes
; taking p and + 4 common
(p + 4)(p – 11)
Factorise.
m2 – 23m + 120
On comparing with standard quadratic equation that is
a
we have,
a = 1, b = – 23 and c = + 120
Now here,
Product a × c = 1 × + 120 = + 120
Factors of + 120; 1 × 120; 2 × 60; 4 × 30; 8 × 15; 24 × 5; 40 × 3
Sum should be b = – 23
From above factors ( – 15m – 8m)
will give – 23m sum
therefore – 23m is replaced by ( – 15m – 8m)
Now above eq. becomes
; taking m and – 8 common
(m – 15)(m – 8)
Factorise.
m2 – 25m + 100
On comparing with standard quadratic equation that is
we have,
a = 1, b = – 25 and c = 100
Now here,
Product a × c = 1 × 100 = 100
Factors of 100; 1 × 100; 2 × 50; 4 × 25;20 × 5
Sum should be b = – 25
From above factors ( – 20m – 5m)
will give – 25m sum
therefore – 25m is replaced by ( – 20m – 5m)
Now above eq. becomes
; taking m and – 5 common
(m – 5)(m – 20)
Factorise.
3x2 + 14x + 15
On comparing with standard quadratic equation that is
we have,
a = 3, b = + 14 and c = + 15
Now here,
Product a × c = 3 × 15 = + 45
Factors of 45; 1 × 45; 5 × 9;15 × 3
Sum should be b = + 14
From above factors ( + 9x + 5x)
will give + 14x sum
therefore + 14x is replaced by ( + 9x + 5x)
Now above eq. becomes
; taking x and + 5 common
(x + 9)(x + 3)
Factorise.
2x2 + x – 45
On comparing with standard quadratic equation that is
we have,
a = 2, b = 1 and c = – 45
Now here,
Product a × c = 2 × – 45 = 90
Factors of 90; 1 × 90; 2 × 45; 10 × 9; 30 × 3
Sum should be b = 1
From above factors ( + 10x – 9x)
will give + x sum
therefore + x is replaced by ( + 10x – 9x)
Now above eq. becomes
; taking 2x and – 9 common
(x + 5)(2x – 9)
Factorise.
20x2 – 26x + 8
On comparing with standard quadratic equation that is
we have,
a = 20, b = – 26 and c = 8
Now here,
Product a × c = 20 × 8 = 160
Factors of 160; 2 × 80; 4 × 40; 8 × 20; 16 × 10; 32 × 5
Sum should be b = – 26x
From above factors ( – 16x – 10x)
will give – 26x sum
therefore – 26x is replaced by ( – 16x – 10x)
Now above eq. becomes
; taking 4x and – 2 common
2(2x – 1)(5x – 4)
Factorise.
44x2 – x – 3
On comparing with standard quadratic equation that is
we have,
a = 44, b = – 1 and c = – 3
Now here,
Product a × c = – 132 = 44 × – 3
Factors of 132; 1 × 132; 2 × 66; 4 × 33;12 × 11
Sum should be b = – 1
From above factors ( – 12x – 11x)
will give – 1x sum
therefore – 1x is replaced by ( – 12x – 11x)
Now above eq. becomes
; taking x and – 9 common
(11x – 3)(4x – 1)
Factorise.
x3 + 64y3
We know that
- - - - - (i)
Here a = 1x, b = 4y; putting values in eq.i
⇒
⇒
}
Note: Must memorize cubes upto 12
Factorise.
125p3 + q3
We know that
- - - - - (i)
Here a = 5p, b = q; putting values in eq.i
⇒
⇒
}
Note: Must memorize cubes upto 12
Factorise.
125k3 + 27m3
We know that
- - - - - (i)
Here a = 5k, b = 3m; putting values in eq.i
⇒
⇒
⇒ }
}
}
Note: Must memorize cubes upto 12
Factorise.
2l3 + 432m3
We know that
- - - - - (i)
Taking 2 common, we get
Here a = l, b = 6m; putting values in eq.i
⇒
⇒
⇒ }]
}
Applying
}
Note: Must memorize cubes upto 12
Factorise.
24a3 + 81b3
We know that
- - - - - (i)
Taking 3 as common, we get
3; solving only bracket term first,
Here a = 2a, b = 3b; putting values in eq.i
}
Applying
}
}
Ans: - 3}
Note: Must memorize cubes upto 12
We know that
- - - - - (i)
Here a = y, b = ; putting values in eq.i
Applying
}
Note: Must memorize cubes upto 12
Factorise.
We know that
- - - - - (i)
Here a = a, b = ; putting values in eq.i
Applying
}
}
Note: Must memorize cubes upto 12
Factorise.
We know that
- - - - - (i)
Here a = 1, b = ; putting values in eq.i
Applying
}
Note: Must memorize cubes upto 12
Factorise :
y3 – 27
We know that
on comparison with above, we get
a = y, b = 3
Note: Must memorize cubes upto 12
Factorise :
x3 – 64y3
We know that
on comparison with above, we get
a = y, b = 3
Note: Must memorize cubes upto 12
Factorise :
27m3 – 216n3
We know that
on comparison with above, we get
a = 3m, b = 6n
Note: Must memorize cubes upto 12
Factorise :
125y3 – 1
We know that
on comparison with above, we get
a = 5y, b = 1
Note: Must memorize cubes upto 12
Factorise :
8p3 – 27/p3
We know that
on comparison with above, we get
a = 2p, b = 3/p
Note: Must memorize cubes upto 12
Factorise :
343a3 – 512b3
We know that
on comparison with above, we get
a = 7a, b = 8b
Note: Must memorize cubes upto 12
Factorise :
64x2 – 729y2
We know that
on comparison with above, we get
a = 4x, b = 9y
Note: Must memorize cubes upto 12
Factorise :
16 a3 – 128/b3
We know that
taking 2 common from above given equation;
on comparison with above, we get
a = 2a, b = 4/b
Note: Must memorize cubes upto 12
Simplify :
(x + y)3 – (x – y)3
We know that
On comparing with given equation we get,
a = (3a + 5b), b = (3a – 5b)
Applying and
Simplify :
(3a + 5b)3 – (3a – 5b)3
We know that
On comparing with given equation we get,
a = (3a + 5b), b = (3a – 5b)
Applying and
Simplify :
(a + b)3 – a3 – b3
We know that
On comparing with given equation we get
Simplify :
p3 – (p + 1)3
We know that
On comparing with given equation we get
a = p, b = 1
Simplify :
(3xy – 2ab)3 – (3xy + 2ab)3
We know that
On comparing with given equation we get,
a = (3xy – 2ab), b = (3xy + 2ab)
Applying and
Simplify:
We know that
applying these equation in above expression, we get
= 1
Note: - Try to factorize that term which help in reducing expression.
Simplify:
We know that
and factorization of numerator and denominator
= a + 1
Note: - Try to factorize that term which help in reducing expression.
Simplify:
We know that
and
Note: - Try to factorize that term which help in reducing expression.
Simplify:
Applying and factorization, we get
= 1
Note: - Try to factorize that term which help in reducing expression.
Simplify:
Applying
and factorization, we get, also changing by reversing N and D
Note: - Try to factorize that term which help in reducing expression.
Simplify:
Applying
and factorization, we get
= x – 2
Note: - Try to factorize that term which help in reducing expression.
Simplify:
Applying
, factorization and we get, also changing by reversing N and D
= 5a + 1
Note: - Try to factorize that term which help in reducing expression.
Simplify:
Applying
and factorization, we get
Note: - Try to factorize that term which help in reducing expression.