Advertisements
Advertisements
Question
Use suitable identity to find the following product:
(3x + 4) (3x – 5)
Advertisements
Solution
Given, (3x + 4) (3x – 5)
Hence, using a suitable identity,
(3x + 4) (3x – 5)
= (3x + 4) [3x + (–5)]
Using the identity (x + a) (x + b) = x2 + (a + b)x + ab, we get that,
(3x)2 + [4 + (–5)]3x + [4 × (–5)]
= 9x2 + (4 – 5)3x + (–20)
= 9x2 + (–1)3x – 20
= 9x2 – 3x – 20
APPEARS IN
RELATED QUESTIONS
Factorise:
4x2 + 9y2 + 16z2 + 12xy – 24yz – 16xz
Factorise the following:
`27p^3-1/216-9/2p^2+1/4p`
Factorise the following:
64m3 – 343n3
Verify that `x^3+y^3+z^3-3xyz=1/2(x+y+z)[(x-y)^2+(y-z)^2+(z-x)^2]`
if `x + 1/x = 11`, find the value of `x^2 + 1/x^2`
Simplify the following products:
`(x^3 - 3x^2 - x)(x^2 - 3x + 1)`
Simplify the expression:
`(x + y + z)^2 + (x + y/2 + 2/3)^2 - (x/2 + y/3 + z/4)^2`
If \[x + \frac{1}{x} = 3\], calculate \[x^2 + \frac{1}{x^2}, x^3 + \frac{1}{x^3}\] and \[x^4 + \frac{1}{x^4}\]
Find the following product:
(7p4 + q) (49p8 − 7p4q + q2)
Find the following product:
If a + b = 8 and ab = 6, find the value of a3 + b3
Evaluate: `(2"x"-3/5)(2"x"+3/5)`
Evaluate: `(2"a"+1/"2a")(2"a"-1/"2a")`
Expand the following:
`(2"a" + 1/(2"a"))^2`
Simplify by using formula :
(1 + a) (1 - a) (1 + a2)
If `"a" + 1/"a" = 6;`find `"a" - 1/"a"`
If 2x + 3y = 10 and xy = 5; find the value of 4x2 + 9y2
Simplify:
(3a + 2b - c)(9a2 + 4b2 + c2 - 6ab + 2bc +3ca)
Simplify:
(3a - 7b + 3)(3a - 7b + 5)
Evaluate the following :
1.81 x 1.81 - 1.81 x 2.19 + 2.19 x 2.19
