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

The y varies directly with x

and for that the equation which we will get is this:

y = kx

and here the k is the slope.

The slope here is 8 because:

3 x = 24

and

7 x 8 = 56

now we will use the slope formula here:

k = 56 - 24/7-3

= 32/4

the answer for this will be 8

So now the function will be y = 8x

The first answer here will be 400 = 8(50) ( this is the only statement which will fit the function)

So the correct answer for this question: 50 - page photo album which will hold 400 photographs.