Answer:
x=1 and y=−2
Step-by-step explanation:
Multiply the first equation by 9,and multiply the second equation by -8.
9(−7x−8y=9)
−8(4x−9y=22)
Becomes:
−63x−72y=81
−32x+72y=−176
Add these equations to eliminate y:
−95x=−95
Then solve−95x=−95for x:
−95x
−95
=
−95
−95
(Divide both sides by -95)
x=1
Now that we've found x let's plug it back in to solve for y.
Write down an original equation:
−7x−8y=9
Substitute1forxin−7x−8y=9:
(−7)(1)−8y=9
−8y−7=9(Simplify both sides of the equation)
−8y−7+7=9+7(Add 7 to both sides)
−8y=16
−8y
−8
=
16
−8
(Divide both sides by -8)
y=−2
