Question

The number of dogs in a shelter is equal to 4 less than 2 times the number of cats. If there are 20 dogs in the shelter how many cats are there?

Answer 1

d=number of dogs
c=cats

d equals 4 less than 2 times c
d=-4+2c
20 dogs
d=20
subsitute
20=-4+2c
add 4
24=2c
divide 2
12=c
12 cats