What is the solution to the system shown? y = x + 4

y - 2x = -1
A.
(-5, -1)
B.
(1, 5)
C.
(5, 9)
D.
(6, 10)

c

Step-by-step 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)

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.