In the first week of July, a record 1,120 people went to the local swimming pool. In the second week, 105 fewer people went to the pool than in the first week. In the third week, 140 more
people went to the pool than in the second week. In the fourth week, 371 fewer people went to the
pool than in the third week. What is the percent decrease in the number of people who went to the
pool over these four weeks?
The percent decrease of people who went to the pool is %,

f

step-by-step explanation:

f

is it 35

step-by-step explanation:

(b) 240

step-by-step explanation:

first, we use the pythagorean formula using the given side lengths to find x. then we use x to find the side lengths. then we add the side lengths to find the perimeter.

pythagorean theorem formula:

a^2 + b^2 = c^2

(x - 20)^2 + (x - 40)^2 = x^2

x^2 - 40x + 400 + x^2 - 80x + 1600 = x^2

x^2 -120x + 2000 = 0

(x - 100)(x - 20) = 0

x - 100 = 0 or x - 20 = 0

x = 100 or x = 20

we see that the solution x = 20 must be discarded because it will give a negative side length and a side length of 0. the only valid solution is x = 100.

perimeter = sum of the lengths of the sides

perimeter = x + x - 20 + x - 40

perimeter = 3x - 60

replace x with 100.

perimeter = 3(100) - 60

perimeter = 300 - 60

perimeter = 240