Question

Find the value of x so that the line passing through (x, 10) and (-4, 8) has a slope of 2/3.

Thanks yall!

Answer 1

x = - 1

Explanation:

Using the slope formula to find the slope m

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (x , 10) and (x₂, y₂ ) = (- 4, 8)

m =
`(8-10)/(-4-x)` =
`(2)/(3)`, that is

`(-2)/(-4-x)` =
`(2)/(3)` ( cross- multiply )

2(- 4 - x) = - 6 ( divide both sides by 2 )

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

- x = 1 ( multiply both sides by - 1 )

x = - 1

Answer 2

x=-1

Explanation:

General equation of line is y=mx+n where m is slope. So, if we use point (-4, 8) and slope in equation we have 8= 2/3.(-4)+n

Then we have n=8+8/3, that is n=32/3

Therefore equation of our line is y=2/3.x + 32/3

For the point (x,10) in equation 10=2/3.x + 32/3

Then we have 2/3.x = - 2/3 then x= -1