in first equation add 10y to both sides so x=(-30) + 10y
Then put this in for x into the 2nd equation so 3y-4(-30 + 10y) = 46
distribute on the left 3y + 120 - 40y = 46
combine like terms -37y + 120 = 46
subtract 120 from both sides -37y = (-74)
divide both sides by -37 and y=2
then put y=2 into x = (-30) + 10y
so x = (-30) + 10(2) which leaves x = (-10)
final answer (-10, 2)