Which equation represents the height, h(t), of the elevator in feet, as a function of t, the number of seconds during which it has been descending?

h(t) = 5t + 500
h(t) = 5t – 500
h(t) = –5t + 500
h(t) = –5t – 500

''We are given that the elevator is descending, so the coefficient of t must be negative. The elevator's initial position is 500 feet above the ground, so this is a positive value of +500. Therefore the only choice that fits is h(t) = -5t + 500.''- Blitztiger

Step-by-step explanation:

The answer above says it's C, so I'm trusting it's C

Step-by-step explanation: Sorry if it's wrong

d. bc = 12 and ef = 16

step-by-step explanation:

we are given that δabc : δdef such that .

also, it is given that

so, from the options, we need that .

a.

b.

c.  

d.

as, we can see that only option d gives the same ratio as i.e. .

hence, the possible lengths are bc = 12 and ef = 16.

5x + 3y = - 4

step-by-step explanation:

the equation of a line in standard form is

ax + by = c ( a is a positive integer and b, c are integers )

express the line first of all in slope- intercept form

y = mx + c ( m is the slope and c the y-intercept )

to calculate m use the gradient formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (7, - 3) and (x₂, y₂ ) = (4, - 8)

m = = -

y = - x + c ← is the partial equation

to find c substitute either of the 2 points into the partial equation

using (4, - 8 ), then

- 8 = - + c ⇒ c = -

y = - x - ← in slope-intercept form

multiply all terms by 3 to eliminate the fractions

3y = - 5x - 4 ( add 5x to both sides )

5x + 3y = - 4 ← in standard form