Advertisements
Advertisements
Question
Using the identity (x + a)(x + b) = x2 + x(a + b) + ab, find the following product
(4x + 3y)(4x + 5y)
Advertisements
Solution
(4x + 3y)(4x + 5y)
Substituting x = 4x, a = 3y and b = 5y
In (x + a)(x + b) = x2 + x(a + b) + ab, we get
(4x + 3y)(4x + 5y) = (4x)2 + 4x(3y + 5y) + (3y)(5y)
= 42x2 + 4x(8y) + 15y2
= 16x2 + 32xy + 15y2
(4x + 3y)(4x + 5y) = 16x2 + 32xy + 15y2
APPEARS IN
RELATED QUESTIONS
Expand.
(3x + 4y) (3x + 5y)
Expand.
`(x + 1/x)(x - 1/x)`
Expand.
`(1/y + 4)(1/y - 9)`
Expand (2n – 1)(2n + 3)
Using the identity (x + a)(x + b) = x2 + x(a + b) + ab, find the following product
(x + 3)(x + 7)
Evaluate the following, using suitable identity
51 × 52
Multiply the following:
(x2 – 5x + 6), (2x + 7)
Using suitable identities, evaluate the following.
104 × 97
Using suitable identities, evaluate the following.
10.1 × 10.2
The following expression is the area of a rectangle. Find the possible length and breadth of the rectangle.
x2 – 3x + 2
