A student told to draw the graph of y = x2 + 4x - 6. He is then told to draw a liner graph on the same axis such that the intersection of the two graphs will give the solutions to the equation x2 + 4x - 7 = 0, What is the equation of the linear graph he needs to draw?
A
x = 1
B
x = -1
C
y = 1
D
y = -1
E
x + y = 1
Verified Correct Answer: C.
Step-by-Step Mathematical Solution
The linear equation will be the difference between the equation.
y=x2 + 4x - 6 and x2 + 4x - 7 = 0
y=x2 + 4x - 6, ( 0 = x2 + 4x - 7)
y = -(-1) y = 1
Source: Myschool Past Questions Archive (Record #22050)