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
Expand the following, using suitable identity:
(2x – y + z)2
Expand the following, using suitable identity:
`[1/4a-1/2b+1]^2`
What are the possible expressions for the dimensions of the cuboids whose volume is given below?
| Volume : 3x2 – 12x |
Simplify the following products:
`(x^3 - 3x^2 - x)(x^2 - 3x + 1)`
Write the expanded form:
`(-3x + y + z)^2`
Evaluate of the following:
933 − 1073
Find the following product:
Find the square of 2a + b.
Evaluate : (4a +3b)2 - (4a - 3b)2 + 48ab.
The difference between two positive numbers is 5 and the sum of their squares is 73. Find the product of these numbers.
Use the direct method to evaluate the following products:
(a – 8) (a + 2)
Use the direct method to evaluate the following products :
(3x – 2y) (2x + y)
Use the direct method to evaluate :
(2a+3) (2a−3)
Use the direct method to evaluate :
`(3/5"a"+1/2)(3/5"a"-1/2)`
Evaluate: `(3"x"+1/2)(2"x"+1/3)`
Evaluate: 20.8 × 19.2
Simplify by using formula :
(5x - 9) (5x + 9)
If `"a" + 1/"a" = 6;`find `"a"^2 - 1/"a"^2`
If a2 - 3a - 1 = 0 and a ≠ 0, find : `"a" - (1)/"a"`
Simplify:
`(x - 1/x)(x^2 + 1 + 1/x^2)`
