Question

The points ( – 5,j) and (5, – 6) fall on a line with a slope of – 7/10 . What is the value of j?

Answer 1

j = 1

Explanation:

calculate the slope m between the 2 points and equate to -
`(7)/(10)`

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

with (x₁, y₁ ) = (- 5, j ) and (x₂, y₂ ) = (5, - 6 )

m =
`(-6-j)/(5-(-5))` =
`(-6-j)/(5+5)` =
`(-6-j)/(10)`

then equating gives

`(-6-j)/(10)` = -
`(7)/(10)` ( cross- multiply )

10(- 6 - j) = - 70 ( divide both sides by 10 )

- 6 - j = - 7 ( add 6 to both sides )

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

j = 1