825 Square feet is the answer
When I had these kinds of problems, I'd count how many negatives there were. If there more or less negatives to positives, then it is negative. If there's the same amount of positives and negatives, then it's positive since they cancel out! The answer to this is A. (-2)(-4)(8)(-1)=-64.
For this case what we have to take into account is the following variable:
x = represent the unknown number
We now write the following inequality:
"four times the sum of number and 15 is at least 20"
4 (x + 15)> = 20
We clear the value of x:
(x + 15)> = 20/4
(x + 15)> = 5
x> = 5 - 15
x> = - 10
The solution set is:
[-10, inf)
Answer:
all possible values for X are:
[-10, inf)
