Answer:
58.6.....................
hi
-16t²+250 = 75
-16t² = 75 -250
-16t² = -175
t² = -175 /-16
t² = 175/16
Here there si two solutions : t =
and t = - 
However, as time cannot rewind, we will keep only positive solution
So t = 
in seconds it will be : 3.3 seconds
Answer:
80 is less than or equal to 22+7x
8 DVDs
Step-by-step explanation:
I don't have the inequality signs sorry if you don't know its the symbol thats opening to the left with a line underneath
80 is less than or equal to 22+7x
subtract 22
58 is less than or equal to 7x
divide and flip the sign to the right
x is greater than or equal to 8.29
so he can buy 8 DVDs in total