Answer:
c
Explanation:
Rewrite equations:
y=x+4;−2x+y=−1
Step: Solvey=x+4for y:
y=x+4
Step: Substitutex+4foryin−2x+y=−1:
−2x+y=−1
−2x+x+4=−1
−x+4=−1(Simplify both sides of the equation)
−x+4+−4=−1+−4(Add -4 to both sides)
−x=−5
−x
−1
=
−5
−1
(Divide both sides by -1)
x=5
Step: Substitute5forxiny=x+4:
y=x+4
y=5+4
y=9(Simplify both sides of the equation)