Lee scored 91 points on a math testOn the next test, she scored 13 fewer pointsOn the third test, she scored 92What is the difference between Lee's highest and lowest scores?

14 points

Step-by-step explanation:

The second test Lee did was 13 points fewer than the first test, which was 91 points, so the second test's score is 91 - 13 = 78 points.

The third test had the score of 92, so this is the highest score, and the lowest score is the second one: 78 points.

The difference between Lee's highest and lowest scores is:

92 - 78 = 14 points

(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

the answer is:

mean: 6

mad: 2.14