Find the ordered pair that satisfies the system of equations
x+3y=−4,3x−7y=36.
+240 Multiply first equation by 3,
3x+9y=−12
3x−7y=36
Subtract,
16y=−48
y=−3
Plug y back into one of the equations,
x−9=−4
x=5
So (x, y) = (5, -3)
+876 $-9x - 27y = 36$
$3x - 7y = 36$
$3x - 7y = -9x - 27y$
$12x = -20y$
$3x = -5y$
$x = - \frac{5}{3} y$
$3x + 9y = -12$
$16y = -48$
$y = -3$
$x = 5$
$(x,y) = (5, -3)$
