Answer:
Step-by-step explanation:
a. Subtract 25, then take the square root.
... 89 = d^2 +25
... 64 = d^2 . . . . . . . . . subtract 25
... ±√64 = d = ±8 . . . . take the square root
b. Subtract 85, then divide by -8.
... 85 -8m = 69
... -8m = -16 . . . . subtract 85
... m = 2 . . . . . . . divide by the coefficient of m
