Question

Solve each system algebraically 3x+6y=-6 5x-2y=14 Help!!

Answer 1

If you multiply the second equation by 3, it becomes:

15x - 6y = 42

Then add the two equations together:

3x + 6y = -6
15x - 6y = 42
+

18x = 36
x = 2

substitute x back into the first equation:

3(2)+6y = -6
6 + 6y = -6
6y = -12
y = -2

So x=2,y=-2

Answer 2

$\left \{ {{3x+6y=-6} \atop {5x-2y=14\ \ | *3}} \right. \\\\ \left \{ {{3x+6y=-6} \atop {15x-6y=42}} \right.\\\+-----\\Addition\ method\\\\ 18x=36\ \ \ | divide\ by\ 18\\\\x=2\\\\2y=5x-14\\\\ y=\frac{5x-14}{2}=\frac{5*2-14}{2} =\frac{10-14}{2}=-2\\\\Solution\\ \left \{ {{y=-2} \atop {x=2}} \right.$