Answer:
The answer is B. (-7,-2)
Explanation:
Multiply the first equation by 7,and multiply the second equation by -6.
7(−3x+6y=9)
−6(5x+7y=−49)
Becomes:
−21x+42y=63
−30x−42y=294
Add these equations to eliminate y:
−51x=357
Then solve−51x=357for x:
−51x=357 Divide both sides by -51
x=-7
Write down an original equation:
−3x+6y=9
Substitute−7forxin−3x+6y=9:
(−3)(−7)+6y=9
6y+21=9(Simplify both sides of the equation)
6y+21+−21=9+−21(Add -21 to both sides)
6y=−12
y=-2