Step-by-step explanation:
multiple ways are possible.
but the easiest might be equation arithmetic, because the y terms are so nicely related.
we multiply the second equation (the whole equation) by 3, and then we add both equations fully :
4x - 6y = 13
-15x + 6y = 15
---------------------
-11x + 0 = 28
-11x = 28
x = -28/11
and that we use in any of the two original equations to get y :
-5x + 2y = 5
-5(-28/11) + 2y = 5
140/11 + 2y = 5 = 55/11
2y = -85/11
y = -85/11 / 2/1 = -85/22
let's make the check :
4×-28/11 - 6×-85/22 = 13
-112/11 + 510/22 = 13
-112/11 + 255/11 = 13
143/11 = 13
13 = 13
correct.
