Jeremy wanted a new drum set for $600. The drums had a scratch on them, so they were discounted down to $492. By what percent did the drums decrease?

18%

Step-by-step explanation:

First you find the difference between 600 and 492 which is 108. Then you divide that difference by the original cost which is .18. Then you multiply that by 100 which is 18%.

$450

step-by-step explanation:

first, you have to multiply 150x2=300

next, you have to add 150+300= 450

(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