Solving Quadratic Equations in Real World

Which of the following is a key step in solving real-world quadratic problems?

• Isolating the variable

• Ignoring the variable

• Graphing the equation

• Using logarithms

Find the roots: x² + 6x + 9 = 0

• x = 6 and x = 5

• x = -2/3 and x = 4

• x = - 3

• x = 0 and x = 2

What are the roots of this function: 5x² - 6x = 0

• x = -7 and x = -8

• x = 6/5 and x = 0

• x = 6 and x = 5

• x = - 4 and x = 3

Heather dropped a water balloon over the side of her school building from a height of 80 feet. The approximate height of the balloon at any point during its fall can be represented by the following quadratic equation: h = -16t² + 80 About how long did it take for the balloon to hit the ground?

• 1.73 seconds

• 2.24 seconds

• 2.45 seconds

• 2.83 seconds

Jason jumped off of a cliff into the ocean in Acapulco while vacationing with some friends. His height as a function of time could be modeled by the function h(t) = –16t² + 16t + 480, where t is the time in seconds and h is the height in feet. How long does it take Jason to hit the water?

• -16 seconds

• -6 seconds

• 0 seconds

• 6 seconds

Members of the math club launch a model rocket from ground level with an initial velocity of 96 ft/sec. This can be modeled with the function h(t) = -16t² + 96t. When does the rocket hit the ground?

• 7 seconds

• 6 seconds

• 3 seconds

• 8 seconds

You jump off a 24 foot high cliff and your fall is modeled by the function:

h(t) = -16t² + 8t + 24

How long would it take you to hit the water?

• 8 seconds

• 1 second

• 1.5 seconds

• 1/4 second

Heather dropped a water balloon over the side of her school building from a height of 80 feet. The approximate height of the balloon at any point during its fall can be represented by the following quadratic equation: h = -16t² + 80 About how long did it take for the balloon to hit the ground?

• 1.73 seconds

• 2.24 seconds

• 2.45 seconds

• 2.83 seconds

Find the solutions: x² - 11x +30 = 0

• x = 4 and x = -3

• x = 6 and x = 5

• x = -2 and x = -6

• x = 8 and x = -8

Solve: (a+1)(a+2)=0

• a = 1, −2

• a = −1, −2

• a = −1, 2

• a = 1, 2