Question

Find the missing coefficient.

(2d - 5)(2d - 4) = 4d^2 + missing coefficient + 20
 
A.) -2
B.) -18
C.) 2
D.) 18

Answer 1

(2d - 5)(2d - 4) = 4d^2 - 2d x 4 - 5 x 2d + 20 = 4d^2 - 18d + 20

Answer is B
Hope it helps!

Answer 2

B) -18

Explanation:

To find the missing coefficient, we have to multiply (2d - 5)(2d -4) using FOIL method.

FOIL method is used to multiply two binomials.

F- Multiply the first terms of each binomials

O-Multiply the outer terms

I- Multiply the inner terms

L-Multiply the last terms

(2d - 5)(2d - 4) = (2d)(2d) +2d(-4) -5(2d) -5(-4)

Simplifying this, we get

4d^2 -8d -10d + 20

Simplify the like terms, we get

4d^2 -18d +20

Here the missing term is -18d

The coefficient is -18

Therefore, answer is -18.