Question

Show all the steps you use to solve this problem in the space provided. Solve the system of equation algebraically. Show all your steps.

Y = x^2 + 2x
Y = 3x + 20

Answer 1

the solutions are (-4, 8) and (5, 35)

Explanation:

Equate these two functions:

Y = x^2 + 2x = Y = 3x + 20, or

x^2 - x - 20 = 0

This easily factors: (x - 5)(x + 4) = 0

and the roots are {-4, 5}

Now find the y value for each:

at x = -4, y = 3(-4) + 20 = 8, and

at x = 5, y = 3(5) + 20 = 35

Thus, the solutions are (-4, 8) and (5, 35)