A ball is launched upward at 48 ft/s from a platform that is 100 ft. high. This can be modeled by the equation
h(t) = -16t? + 48t + 100
How long does it take the ball to reach its maximum height?

let x and 400 - x be the two numbers.  

==> 0.80x + 0.85(400 - x) = 400 - 68 from the statement of the problem.  

< ==> 0.80x + 0.85(400 - x) = 400 - 68  

==> 340 - 0.05x = 332  

< ==> -0.05x = -8 ==> x = 160, the first number ==> 400 - x = 240, the second number.

answer is (b.

164 ft2)

a base  

18

b base  

7

h height  

8