SOLUTION: If x^2 + 7x - 8 = 0 ans y = x - 5, then what are the possible values of y? (A)-8 and 0.1 (B) -8 and -13 (C) 1 and -4 (D) -3 and -4 (E) -13 and -4

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: If x^2 + 7x - 8 = 0 ans y = x - 5, then what are the possible values of y? (A)-8 and 0.1 (B) -8 and -13 (C) 1 and -4 (D) -3 and -4 (E) -13 and -4      Log On


   

Question 338630: If x^2 + 7x - 8 = 0 ans y = x - 5, then what are the possible values of y?
(A)-8 and 0.1 (B) -8 and -13 (C) 1 and -4 (D) -3 and -4 (E) -13 and -4
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.x%5E2+%2B+7x+-+8+=+0
2.+y+=+x+-+5
From eq. 1,
%28x%2B8%29%28x-1%29=0
Two solutions:
x%2B8=0
x=-8
Then from eq. 2,
y=-8-5
highlight%28y=-13%29
.
.
.
x-1=0
x=1
Then from eq. 2,
y=1-5
highlight%28y=-4%29