Find the missing coefficient.

(5d - 7)(5d - 6) = 25d^2 + _d + 42

1 answer

To find the missing coefficient, we need to multiply the terms in the given binomials:

(5d - 7)(5d - 6) = (5d)(5d) + (5d)(-6) + (-7)(5d) + (-7)(-6)
= 25d^2 - 30d - 35d + 42
= 25d^2 - 65d + 42

The missing coefficient is -65d.