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.
(p + 8) (p − 3)
Expand.
(13 + x) (13 − x)
Expand: (x + 2)(x + 3).
Expand: (2a + 3b)(2a - 3b).
Using the identity (x + a)(x + b) = x2 + x(a + b) + ab, find the following product
(6a + 9)(6a – 5)
Using the identity (x + a)(x + b) = x2 + x(a + b) + ab, find the following product
(8 + pq)(pq + 7)
Multiply the following:
(x2 – 5x + 6), (2x + 7)
Using suitable identities, evaluate the following.
98 × 103
The following expression is the area of a rectangle. Find the possible length and breadth of the rectangle.
x2 + 9x + 20
