Step-by-step explanation:
You're asking why

let's transpose the first equation for y
-2x-6y=18
-6y=18+2x
6y=-18-2x
y=-18/6-2x/6
y=-3-⅓x as required
Answer:
5
Step-by-step explanation:
5 / 4 = 20 20 - 8 =12
Awnser
y=13
Step-by-step explanation:
-3x+2y=56
-5x-2y=24
so first we want to get rid of one variable, in this example we dont need to multiply because the y's cancel out
so we have
-8x=80
x=-10
now plug in x into an original equation
-3(-10)+2y=56
2y=26
y=13
hope that helps