Question

A line has a slope of -1/7 and includes the points (10, 3) and (j, 4). What is the value of j?

Answer 1

Answer:

j = 3

Step-by-step explanation:

calculate the slope m, of the 2 given points and equate to - $\frac{1}{7}$

calculate the slope m , using the slope formula

• m = $\frac{y_{2}-y_{1} }{x_{2}-x_{1} }$

let (x₁, y₁ ) = (10, 3 ) and (x₂, y₂ ) = (j, 4 )

substitute these values into the formula for m

m = $\frac{4-3}{j-10}$ = $\frac{1}{j-10}$

now equate to - $\frac{1}{7}$

$\frac{1}{j-10}$ = - $\frac{1}{7}$ ( cross multiply )

j - 10 = - 7 ( add 10 to both sides )

j = 3