Geoffrey is 6 years older than Dion Geoffrey is 12 years old which equation represents how old Diane is A.12=d-6
b:6+12=d
c:d-6=12
d:12=d+6​

You have to give us options

1. isolate the variable, in this case, d. subtract 35.5 on both sides of the equation.2. 52 subtracted by 35.5 is 16.53. therefore your answer would be d= 16.5this is the basics of pre algebra, isolating variable through adding, subtracting, multiplying, and dividing, if you have any other questions to ask just comment!