Find the missing coefficient.
(5d – 7)(5d – 6) = 25d^2 + __d + 42
To find the missing coefficient, we need to expand the left side of the equation (5d - 7)(5d - 6):
(5d - 7)(5d - 6)
= 25d^2 - 30d - 35d + 42
= 25d^2 - 65d + 42
Comparing this with the given expression 25d^2 + __d + 42, we can see that the missing coefficient is -65.
Therefore, the complete expression is:
25d^2 - 65d + 42