The area of a square is increasing at a rate of 2 square feet a second. If the square started with an area of 4 square feet, how much time passes before the area of the square equals 16 square feet

  6 seconds

Step-by-step explanation:

The area of interest increases from 4 square feet to 16 square feet, an increase of 12 square feet. Since the area increases by 2 square feet each second, the time required for it to increase 12 square feet is ...

  (12 square feet)/(2 square feet/second) = 6 seconds

b

step-by-step explanation:

the equation of a line in point- slope form is

y - b = m(x - a)

where m is the slope and (a, b) a point on the line

calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (0, 4) and (x₂, y₂ ) = (3, - 5) ← 2 points on the line

m = = = - 3

with m = - 3 and (a, b) = (3, - 5), then

y - (- 5) = - 3(x - 3), that is

y + 5 = - 3(x - 3) → b