Solving Quadratic Equations Review

Alain throws a stone off a bridge into a river below. The stone's height (in meters above the water), x seconds after Alain threw it, is modeled by:

h(x)= -5x² + 10x + 15

How many seconds after being thrown will the stone hit the water?

• -1 seconds

• 1 second

• 2 seconds

• 3 seconds

An object is launched upward and the height of the object is represented by the equation s(t) = –16t² + 64t + 80. How long does it take for the object to hit the ground after it has been launched?

• 2 seconds

• 5 seconds

• 80 seconds

• 0 seconds

Find the solution(s).

Find the solution(s):

y = x² - 4x + 6

y = x + 2

The quadratic function y = -2x² + 4x + 6 is pictured. What are the solutions to the equation 7.5 = -2x² + 4x + 6?

• x = 0.5

• x = 1.5

• x = 1

• x = 8

• x = 6

What are the solutions to the quadratic equation?

• x = -4

• x = 1

• x = -1

• x = 2

• x = 4

What are the solutions for this quadratic equation?

• -4 and 0

• 4 and 0

• -2 and 4

• -2 and -4

Select the solutions to the equation

4x² + 11x + 7 = 0

• x = - 1.75

• x = 6

• x = - 1

• x = 1

x² - 9x + 20 = 0

• x = -4 and x = -5

• x = 20 and x = -9

• x = 4 and x = 5

• x = -4 and x = 5

x² + 2x - 24 = 0

• x = -6, x = 4

• x = 6, x = -4

• x = 12, x = -2

• x = 8, x = -3