Swimmers best time in event is 53.87 seconds. On average, his best time decreases by 0.28 seconds each of the next five times he swims the event. Does he accomplish his goal of swimming the event in less than 52.5 seconds?

Yes. This is because his fifth attempt was 52.47 seconds

Step-by-step explanation:

From the question, we are informed that Swimmers best time in event is 53.87 seconds and that on average, his best time decreases by 0.28 seconds each of the next five times he swims the event.

The time for the fifth time he swim will be:

= 53.87 - 5(0.28)

= 53.87 - 1.4

= 52.47 seconds

This means that he accomplish his goal of swimming the event in less than 52.5 seconds.

55% are girls and 45% are boys : ) hope this

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