Question

Find the value of a so that the

line that passes through (-5, a) and (1, -10) has a

slope of -4/3

Answer 1

Using the slope formula,
`m=(y_2-y_1)/(x_2-x_1)`, we can substitute in the known slope and the points:

`-(4)/(3)=(-10-a)/(1-(-5))`

Cleaning that up a bit:

`-(4)/(3)=(-10-a)/(6)`

Then multiply both sides by 6:

`(6)/(1)\cdot\left(-(4)/(3)\right)=(6)/(1)\left((-10-a)/(6)\right)`

`-8 = -10-a`

Add 10 to both sides:

`2= -a`

Divide both sides by -1:

`-2 = a`

a = -2