Answer:
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