Question

A system of two equations contains one quadratic equation and one linear equation. the quadratic system of the equation is y=x^2+5x-9. the solutions of the system are (3,15) and (-1,-13). what is the linear equation in the system?
Help if you don't mind!

Answer 1

Suppose the line is y=mx+b
when x=3, y=15, so 15=3m+b
when x=-1, y=-13, so -13=-m+b
solve the system of these two equation, you get m=7, b=-6
so the linear equation is y=7x-6