Answer:
x=−2
y=−4
Explanation:
−2x+2y=−4
3x+3y=−18
In order to solve by elimination, coefficients of one of the variables must be the same in both equations so that the variable will cancel out when one equation is subtracted from the other.
−2x+2y=−4,3x+3y=−18
To make −2x and 3x equal, multiply all terms on each side of the first equation by 3 and all terms on each side of the second by −2.
3(−2)x+3×2y=3(−4),−2×3x−2×3y=−2(−18)
Simplify.
−6x+6y=−12,−6x−6y=36
Subtract −6x−6y=36 from −6x+6y=−12 by subtracting like terms on each side of the equal sign.
−6x+6x+6y+6y=−12−36
Add −6x to 6x. Terms −6x and 6x cancel out, leaving an equation with only one variable that can be solved.
6y+6y=−12−36
Add 6y to 6y.
12y=−12−36
Add −12 to −36.
12y=−48
Divide both sides by 12.
y=−4
Substitute −4 for y in 3x+3y=−18. Because the resulting equation contains only one variable, you can solve for x directly.
3x+3(−4)=−18
Multiply 3 times −4.
3x−12=−18
Add 12 to both sides of the equation.
3x=−6
Divide both sides by 3.
x=−2
The system is now solved.
x=−2,y=−4