Ok. In order to do this set up 2/5 divided by 5/7. The way you divide with fractions is by multiplying them but flipping the second fraction into 7/5 <---this is known as the reciprocal. In other words do:
2/5 x 7/5 =
14/25
There you go.
False, because the number 40 is a composite number, those that cannot be broken down are called Prime Numbers.
Prime numbers are numbers that are used to decompose any number, but prime numbers cannot be decomposed, since they only have two Divisors, which are 1 and itself.

Answer:
16
Step-by-step explanation:
Add 13 both sides
That would give you 5v=80
Divide 80 by 5. So v would equal 16
The answer would be C. We know that d is equal to the initial depth of a lake. The two given initial depths are 58 feet and 53 feet, so we know that one of the equations must be either d=58 or d=53. Because there only C has either one of those, d=58, we know that it must be the answer.
To find the other equation, it is just a linear function for the other lake. The y-intercept, or initial value, is 53, so in the equation y=mx+b, it is the b value. The slope, or m value, is 3 feet, so you have y=d=3x+53.
Water = 5 bottles * $0.90 = $4.50
meat = 8 pounds * x amount.
Total = water + meat prices = $26.90
26.90 = $4.50 + 8x
22.40 = 8x
2.8 = x
The price per pound of meat is $2.80.