Question

3x-5y=-6 -9x-5y=18 whats the answer

Answer 1

$\left \{ {{3x-5y=-6\ \ | *3} \atop {-9x-5y=18}} \right. \\\\ \left \{ {{9x-15y=-18} \atop {-9x-5y=18}} \right. \\+----\\add\ both\ equations\\\\ -20y=0\ \ \ | divide\ by \ -20\\\\ y=0\\\\ 3x-5y=-6\ \ \ \ add\ 5y\\\\ 3x=-6+5y\ \ \ | divide\ by\ 3\\\\ x=\frac{-6+5y}{3}=\frac{-6+0}{3}=-2\\\\ x=-2\\ y=0$

Answer 2

We can eliminate the  y term by multiplying by -1 and adding
-9x-5y=18
multiply -1
9x+5y=-18
add
     3x-5y=-6
  + 9x+5y=-18
     12x+0y=-24
12x=-24
divide by 12
x=-2

subsitute
3(-2)-5y=-6
-6-5y=-6
add 6 to both sides
-5y=0
y=0

x=-2
y=0