Question

10
11 5(2x + 1) + c(x + d) = 12x - 1
Work out the value of c and the value of d.

Answer 1

c = 2, d = - 3

Explanation:

Expand and simplify the left side then compare the coefficients of like terms on both sides.

5(2x + 1) + c(x + d) ← distribute parenthesis

10x + 5 + cx + cd

= x(10 + c) + 5 + cd

Compare like terms on both sides, that is

10 + c = 12 ( subtract 10 from both sides )

c = 2

Then

5 + cd = 5 + 2d and

5 + 2d = - 1 ( subtract 5 from both sides )

2d = - 6 ( divide both sides by 2 )

d = - 3