Question

Alex's dog weighs 7 times as much as her cat. Together, the two pets weigh 72 pounds. How much does Alex's dog weigh?

Answer 1

D=dog's weight
c=cat's weight
d=7c
d+c=72
sub 7c for d
7c+c=72
8c=72
divide both sides by 8
c=9
d=7c
d=7(9)
d=63
dog=63lb