contestada

Y = x2 + 5x + 4 and y = 2x2 + 3x – 59 are shown. what are the coordinates of the points of intersection of the 2 graphs?

Respuesta :

y =  x² + 5x + 4
y = 2x²+ 3x - 59

Use substitution method to solve the system of equations:
x² + 5x + 4 = 2x²+ 3x - 59
               0 =   x² - 2x - 63
               0 = (x - 9)(x + 7)
               0 = x - 9, 0 = x + 7
               9 = x      -7 = x

when x = 9,  y = (9)² + 5(9) + 4 → y = 81 + 45 + 4 = 130    (9, 130)
when x = -7,  y = (-7)² + 5(-7) + 4 → y = 49 - 35 + 4 = 18    (-7, 18)

Answer: the points of intersection are (9, 130) and (-7, 18)