Question

PLEASE HELP DUE IN 30 MINUITES

The slope of a line is 5. A (2, 1) is a point on the line. Another point, B, on the line has y=81. What is the x-value at this point, as denoted by d?

Answer 1

the x-value is 17

Explanation:

slope = (y2 - y1) / (x2 - x1) = (81 - 1) / (x - 2) = 5

80 / (x - 1) = 5

x - 1 = 16

x = 17

hope this helps! <3

Answer 2

the x-value is 18

Explanation:

Ok so the slope-intercept form can be represented as:
`y=mx+b` where m=the slope, and b=y-intercept

we're given the slope, so we can form the equation:
`y=5x+b`, but we still don't know the y-intercept.

We can solve for this using the point given, which we can substitute in known values:

substituting in 2 as x, and y as 1

`1=5(2)+b`

Multiply:

`1=10+b`

Subtract 10 from both sides

`-9=b`

Now we have the full equation:

`y=5x-9`

So, now we're given another point, but this one is incomplete, we just have the y-value, so the point can be represented as (x, 81)

We can substitute in this known value to solve for x

`81 = 5x-9`

Add 9 to both sides

`90=5x`

Divide both sides by 5

`18=x`