A=74%
B=$321.75
if my calculations are correct.
Variable
Step-by-step explanation:
(x-1)^2=9 <=> x-1=3 <=> x=4
F ( x ) = - x² + 5 x + 4
between x = 3 and x = 5:
f ( 3 ) = - 3² + 5 · 3 + 4 = - 9 + 15 + 4 = 10
f ( 5 ) = - 5² + 5 · 5 + 4 = - 25 + 25 + 4 = 4
Average rate of change:
( 4 - 10 ) / ( 5 - 3 ) = - 6 : 2 = - 3 feet / sec
