solve by the elimination method

3r - 7s =-29
7r + 3s = 29

What is the solution of the system?
Type an ordered pair. Type an interger or a fraction or type N if there is no solution or type 1 if there are infinitely many solutions.

This can be solved as there are two unknowns and two equations.

I would multiply the top by 3 and the bottom by 7 and then add the two equations together.

9r-21s=87
49r+21s=203
add
58r=290

r=5

subsiitute in the first equation

15-7s=29

7s=-14 so s=-2