Question

5x+7y=31
2x+4y=16

solve the given system of equations by the addition method?

Answer 1

multiply first equation by 2
and second by (-5) and add together.
what would you get?

Answer 2

10x+14y=62
-10x-20y=-80
------------- (+)

Answer 3

-6y=-18
y=....?

Answer 4

y=3
substitute value of y=3 in any given equation - I'll do it with the first one:
5x+7*3=31
5x=31-21
x=10/5
x=2

So the final answer would be:
x=2 and y=3

Got to go. Good Luck!