Justin was interested in knowing the range of xvalues for wh

Justin was interested in knowing the range of x-values for which the ball will be higher than 60 feet. He uses the path of the ball to write the following inequality:

For which range of x-values is y greater than 60? Write your answer in the form a < x < b, and enter the values for a and b.

Solution

-0.1x^2 +8x -60 > 60

solve the inequality :

-0.1x^2 +8x -120 >0

-x^2/10 +8x -120 >0

-x^2 +80x -1200 >0

x^2 -80x +1200 <0

(x-20(x-60) <0

Choosing the range for which inequality <0

20 <x < 60

a = 20 ; b = 60