On the set of axes, solve the following system of equations graphically for all values of
x and y. State the coordinates of all the solutions.
y = x2 + 4x - 5
y = 2x +


Sagot :

y = x² + 4x - 5
y = 2x

x² + 4x - 5 = 2x
     - 2x       - 2x
x² + 2x - 5 = 0
x = -(2) ± √((2)² - 4(1)(-5))
                   2(1)
x = -2 ± √(4 + 20)
               2
x = -2 ± √(24)
             2
x = -2 ± 2√(6)
             2
x = -1 ± √(6)
x = -1 + √(6)    U    x = -1 - √(6)
y = 2x
y = 2(-1 ± √(6))
y = 2(-1) ± 2√(6)
y = -2 ± 2√(6)
(x, y) = (-1 ± √(6), -2 ± 2√(6))