Answer:
Solution: (1,-2)
Step-by-step explanation:
System of Equations
Given the equations:
[tex]-7x-8y=9\qquad\qquad [1][/tex]
[tex]-4x+9y=-22\qquad\qquad [2][/tex]
We'll solve it by elimination. It means eliminating one of the variables by equating their coefficients. We select the variable y. To eliminate it, multiply the equation [1] by 9 and the equation[2] by 8:
-63x-72y=81
-32x+72y=-176
Adding up both equations:
-95x=-95
Solving:
x=-95/(-95)=1
x=1
Now to eliminate x and find y, multiply [1] by 4 and [2] by -7:
-28x-32y=36
28x-63y=154
Adding up both equations:
-95y=190
Solving:
y=190 / (-95) = -2
y=-2
Solution: (1,-2)
