7x - 4y = 0......multiply by -2
2x + 7y = 57...multiply by 7
-----------------
-14x + 8y = 0 (result of multiplying by -2)
14x + 49y = 399 (result of multiplying by 7)
----------------add
57y = 399
y = 399/57
y = 7
7x - 4y = 0
7x - 4(7) = 0
7x - 28 = 0
7x = 28
x = 28/7
x = 4
so ur solution is (4,7) with the y value being 7 <==
