Question

The points (3, 24) and (7, 56) represent points of a function where y, the number of photographs, varies directly with x, the number of pages in an album. Which statement describes another point on the graph of this function?

A 50-page photo album holds 400 photographs.
An 80-page photo album holds 560 photographs.
A 100-page photo album holds 8,000 photographs.
A 900-page photo album holds 8,400 photographs.

Answer 1

Yes ! The correct answer is A.) 50-page photo album holds 400 photographs.

Explanation:

I did the Unit Test and i got it correct.

Answer 2

Option A 50-page photo album holds 400 photographs.

Explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
`y/x=k` or
`y=kx`

step 1

Find the value of k

For the point (3,24)

x=3,y=24

k=y/x

k=24/3=8

The equation is equal to

y=8x

step 2

Verify each statement

case A) 50-page photo album holds 400 photographs.

For x=50

substitute in the equation

y=8(50)=400 -----> is correct

case B) 80-page photo album holds 560 photographs.

For x=80

substitute in the equation

y=8(80)=640 -----> is not correct

case C) 100-page photo album holds 8,000 photographs.

For x=100

substitute in the equation

y=8(100)=800 -----> is not correct

case D) 900-page photo album holds 8,400 photographs.

For x=900

substitute in the equation

y=8(900)=7,200 -----> is not correct