how do you work out 5x-2y=4

Question

3x+y=9

Answer 1

by "work out" do you mean solve ?

double the second and add to the first

5x-2y=4
6x+2y=18

11x = 22
x = 2

sub into original 2nd
3(2) + y = 9
y = 9-6
y = 3