The expression - 350 + 19m represents a submarine that began at a depth of 350 feet below sea level and ascended at a rate of 19 feet per minute. What was the depth of the submarine after 7
minutes?
Select the correct answer below and, if necessary, fill in the answer box to complete your choice.
A. The submarine was feet below sea level after 7 minutes.
OB. The submarine will have reached sea level after 7 minutes.

A. The submarine was 217 feet below sea level after 7 minutes

Step-by-step explanation:

-350+19(7)

-350+133

-217

Since the answer is negative, the submarine was bellow sea level.

idk sry

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