HELP ME PLEASEE IM NOT UNDERSTANDING THIS

  (10, 1), (15, 1), (20, 13), (25, 7)

  IS a function

Step-by-step explanation:

The ordered pairs are (input, output). Essentially, the numbers in each ordered pair are the numbers at each end of an arrow. There are as many ordered pairs as there are arrows.

Working top-down on input values, the ordered pairs of this relation are ...

  (10, 1), (15, 1), (20, 13), (25, 7)

None of the input values is repeated, so the relation is a function.

the answer will be

(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