Steve has a dog that weighs 5 times as much as ian's dog. the total weight of both dogs is 72 pounds. how much does steve's dog weigh?

S=steve's dog's weight
i=ian's dog's weight

so steve's dog weighs 5 times of ians dog
s=5 times i
s=5i
total weight=72
s+i=72
we can subsitute 5i for s since s=5i
5i+i=72
add
6i=72
divide by 6
i=12

find s
s+i=72
s+12=72
subtract 12
s=60

weighs 60 pounds