Answer:
42d = -252 (since 42 is multiplied by d, you have to divide by 42 on both sides to get what d is)
d= -6
20 = n / (-4) (since n is being divided by -4, you have to multiply by -4 on both sides to get what n is)
n= -80
Explanation:
to get what the variable is, you have to "undo" the operation that is being done.