Step-by-step explanation:
If x is the volume of the first tank, and y is the volume of the second tank, then:
x + y = 55
x = 2y + 4
Solve the system of equations using either substitution or elimination. Using substitution:
2y + 4 + y = 55
3y + 4 = 55
3y = 51
y = 17
Solve for x using either equation.
x + 17 = 55
x = 38
The first tank holds 38 gallons, and the second tank holds 17 gallons.
Answer:
Sample size minimum is 60
Step-by-step explanation:
given that you want to create a 99% confidence interval with a margin of error of .5.
The population standard deviation is equal to 1.5
i.e. 
Confidence level = 99%
Since population std deviation is known, we can use Z critical value for finding margin of error
Z critical value for 99% = 2.58
Margin of error = 
Equate this to 0.5 and solve for n

Answer:
8(6-x)
Step-by-step explanation:
Both 48 and 8 can be divisible by 8.
48 ÷ 8 = 6
8 ÷ 8 = 1
Therefore you get the answer 8(6-x)
as the simplest form.
Hope this helps.