Question

erin and susan both took their dogs for a walk. Together theyw alked 15 miles. If erin walked 3 miles less than susan how far did susan walk with her dog?

Answer 1

e=s-3
e+s=15
Replace e in the second equation wis s-3 from the first equation and solve.

Answer 2

Let distance covered by susan = x miles
then distance covered by erin = (x - 3) miles
together they walked 15 miles
menas
x + (x - 3) = 15
2x - 3 = 15
2x = 15 + 3
x = 18/2
x = 9

so susan walked 9 miles
and erin walked (9-3) = 6 miles