Question

5x+2y=31
2x+y=13

Answer 1

This is a solving systems question.

Answer 2

So you multiply the bottom equation by 2....

Answer 3

to continue what @TRavi14 started, subtract the eqns to eliminate y and solve for x. with this value of x substitute in either eqn to find y

to solve by substitution
using the 2nd eqn y= 13 - 2x substitute this expression for y in the 1st eqn. solve for x use this value in the expression to find y

the 3rd method is by graphing but for this problem it's better to use one of these

Always remember to check your answer in the original eqn.