Answer:
Multiply the first equation by 4.
Step-by-step explanation:
4(x+y=3) which gives
4x+4y=12
and
4x-y=7
Then subtract the two equations and the x variable will be eliminated.
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:
300 gallons an hour
Step-by-step explanation:
If it pumps 75 gallons in 1/4 of an hour (15 minutes), then if you times that by four to make it a full hour (60 minutes). 75 times 4 is 300.
A: 292892 b: 2972 c: 9272726: d: 196373
Answer:
12 feet
Step-by-step explanation:
If we use a rectangle. there would be 4 sides the length we can represent as x and the width would result as 3x. If we use the perimeter formula, we would get 8x. 8x would equal 96, the perimeter.
8x= 96
x= 12
The length would be 12
Hope this helped!! :D