Three guinea pigs living in the same cage need at least 12 square feet of living spàce. is a cage that measure 3 feet by 5 feet big enough for three guineabpigs

Yes, there is enough space . If the guinea pigs need 12 feet, and 5*3= 15 feet  then they have enough.
( idk if means 12 feet of living space for each or all 3 , but here i hope it helps :) )

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!