Answer:
x is greater than -2 and less than or equal to 3
Step-by-step explanation:
so the 3x + 1 is greater than -5
so 3x is greater than -6
we divide both sides by 3
then we find out that x is greater than -2
we also know that 3x + 1 is less than or equal to 10
so 3x is less than or equal to 9
we divide both sides by 3
then we find out that x is less or equal to 3
so we can say that x is greater than -2 and less than or equal to 3
Y≤x/3-1 AND y≤x/3-3
So for BOTH inequalities to be true:
y≤x/3-3
Letter B would be the correct answer
Suppose the larger pump alone can empty the tank in L hours, and the smaller pump can finish the job in S hours, then each hour the large pump empties 1/L portion of the tank, and the small pump empties 1/S per hour
Working together for three hours, they empty the whole tank, which is 100% of it, so 3/L+3/S=100%=1
Larger pump can empty the tank in 4 hours less than the smaller one, so L=S-4
replace L: 3/(S-4)+3/S=1
Make the denominator the same to solve for:
3S/[S(S-4)] +3(S-4)/[S(S-4)]=1
(3S+3S-12)/[S(S-4)]=1
(3S+3S-12)=[S(S-4)]
S^2-10s+12=0
use the quadratic formula to solve for S
S is about 8.6
The answer is not whole hour.
