Question

Solve the system of equations.

y=x+5
y=x2+5x−7

Answer 1

Please use " ^ " to denote exponentiation: y=x^2+5x−7.

Borrow "x+5" from the first equation and replace y in the second with that:

x+5 = x^2 + 5x - 7. Then x^2 + 5x - 7 - x - 5 = 0, or x^2 + 4x -12 = 0.

This is easily factored: (x-2)(x+6)=0, so that x=2 and x=-6.

Using y = x+5, find y for x=2 and then y for x=6.