Question 1012542
5r - 6s = -25 ------ (1)
6r - 5s = 31 ------ (2)

Multiply (2) with 5 and (1) with 6 and then subtracting (2) from (1)

6(5r - 6s) - 5(6r - 5s) = 6(-25) - 5(31)

Can take this forward from here?