Solve using elimination
-x+4y = -19
-3x+3y = 6
Answers
Answer:
x = -9, y = -7
Step-by-step explanation:
Equation (1) -x + 4y = -19
Equation (2) -3x + 3y = 6
Multiply ALL of equation (1) by 3 so that both equations include -3x in it.
(1) 3(-x + 4y = -19)
Simplify.
-3x + 12y = -57 → equation (3)
Now, subtract equation (3) from equation (2).
-3x + 12y = -57
(-)
-3x + 3y = 6
Simplify.
9y = -63
Divide both sides by 9.
9y ÷ 9 = -63 ÷ 9
Simplify.
y = -7
Now that we have the value for y, simply plug in -7 for y into equation (1).
(1) -x + 4y = -19
-x + 4(-7) = -19
Simplify.
-x - 28 = -19
Add 28 to both sides of the equal sign.
-x - 28 + 28 = -19 + 28
Simplify.
-x = 9
Divide both sides by -1.
x = -9
Now we know that : x = -9, y = -7
To check our work, simply plug in -9 for x and -7 for y into equation (1).
(1) -x + 4y = -19
-(-9) + 4(-7) = -19
Simplify.
9 - 28 = -19
-19 = -19
Therefore, x = -9, y = -7