If these numbers represent elevations in meters, which is the farthest away from sea level?

Option (1)

Step-by-step explanation:

Minus notation of the elevations from the sea level represents the distance below the sea level and positive notation represents the elevations above the sea level.

+7 → 7 meters above the sea level

-3 → 3 meters below the sea level

→ 0.5 meters above the sea level

-0.8 → 0.8 meters below the sea level

+0.8 → 0.8 meters above the sea level

→ 0.1 meters below the sea level

-2 → 2 meters below the sea level

Therefore, +7 meters above the sea level will be the farthest point from the sea level.

Option (1) will be the answer.

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.

(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