Answer
{3,1}
Explaination
3 +4=7[1] x = -4y + 7
// Plug this in for variable x in equation [2]
[2] 4•(-4y+7) - 3y = 9
[2] - 19y = -19
// Solve equation [2] for the variable y
[2] 19y = 19
[2] y = 1
// By now we know this much :
x = -4y+7
y = 1
// Use the y value to solve for x
x = -4(1)+7 = 3
Solution :
{x,y} = {3,1}
