Advertisements
Advertisements
Question
Expand the following, using suitable identities.
(x + 3)(x + 7)
Sum
Advertisements
Solution
We have,
(x + 3)(x + 7) = x2 + (3 + 7)x + 3 × 7 ...[Using the identity, (x + a)(x + b) = x2 + (a + b)x + ab]
= x2 + 10x + 21
shaalaa.com
Is there an error in this question or solution?
Chapter 7: Algebraic Expression, Identities and Factorisation - Exercise [Page 232]
APPEARS IN
RELATED QUESTIONS
Show that `(4pq + 3q)^2 - (4pq - 3q)^2 = 48pq^2`
Show that (a - b)(a + b) + (b - c) (b + c) + (c - a) (c + a) = 0
Simplify the following using the formula: (a − b)(a + b) = a2 − b2: (467)2 − (33)2
Simplify the following using the identities: 1.73 × 1.73 − 0.27 × 0.27
Find the value of x, if 14x = (47)2 − (33)2.
Evaluate the following: 994 × 1006
Expand the following:
(2x + 3y + 4z)2
Multiply the following:
(3x2 + 4x – 8), (2x2 – 4x + 3)
Carry out the following division:
76x3yz3 ÷ 19x2y2
Perform the following division:
(ax3 – bx2 + cx) ÷ (– dx)
