Question

Julia plays volleyball and finished the regular season with 25 digs. The graph relates her total number of digs for the season to the number of games played in the post-season tournament.

What is the equation in standard form that represents the relationship shown in the graph?

A. y = 3x + 25
B. 3x + y = 25
C. y = -3x + 25
D. -3x + y = 25
E. y - 37 = 3(x - 4)

Answer 1

Standard form: -3x + y = 25

Explanation:

y=mx+b

y = 3x + 25 ... you want to convert to standard form (Ax+By=C)

-3x -3x ... you want the variables on the left side of the equation

-3x + y = 25

Answer 2

We need to find an equation in the form
`y=mx+b`.

To find
`m`, we use the formula:

`m=(y_(2)-y_(1))/(x_(2)-x_(1))`

We'll use the points
`(0, 25)` and
`(4, 37)`:

`m=(37-25)/(4-0)=(12)/(4)=3`

The value of
`b` (the y-intercept) is the value of
`y` when
`x=0`, which is 25.

So the equation is
`y=3x+25` (choice A).