Ascientist uses a submarine to study ocean life. she begins at sea level, which is at an elevation of 0 feet she travels straight down for 90 seconds at a speed of 3.5 feet per second. she then travels directly up for 30 seconds at a speed of 2.2 feet per second. after this 120-second period, how much time, in seconds, will it take for the scientist to travel back to sea level at the submarine’s maximum speed of 4.8 feet per second? round your answer to the nearest tenth of a second.

answer

explanation

the area of a circle is calculated using the formula

or

we can use any of the above formulae to calculate the required. preferably, let us use the latter since the diameter is

we substitute the diameter into the formula to get:

this is the exact value for the area of the circle.

the correct answer is a

answer: standard form is ax^2 + bx + c = 0

step-by-step explanation:

standard form is ax^2 + bx + c = 0

(2x + 1)(x - 2) = 0

distribute to get into standard form

2x^2 - 4x + x - 2 = 0

2x^2 - 3x - 2 = 0

a = 2, b= -3, c = -2

a is your answer