T = t-shirts & S = shorts

T + T + S + S = $42
T + S + S + S = $45

HOW MUCH IS A PAIR OF SHORTS?
EXPLAIN HOW YOU FOUND THE ANSWER.

2 answers

2T + 2S = 42

Divide both sides by 2.

T + S = 21

T + 3S = 45

Subtract second equation from the first.

2S = 24

Divide both sides by 2.

S = 12

You should be able to work it from here.
Subtract second equation from the third. (sorry)

Also, please only post your questions once. Repeating posts will not get a quicker response. In addition, it wastes our time looking over reposts that have already been answered in another post. Thank you.