Answer:
the solutions are (-4, 8) and (5, 35)
Step-by-step 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)