Question

If the slope is 7, and the given coordinates are (x , 8) and (4 , 1), how do you find x?

Answer 1

There's a formula for slope:

`(Deltay)/(Deltax) = (y_2 - y_1)/(x_2 - x_1) = "slope"`

`"slope" = 7 = (1 - 8)/(4-x_1) = (1 - 8)/(4-x)`

`7(4-x) = -7`

`28 - 7x = -7`

`35 = 7x`

`x = 5`

And for the big picture:

`y = mx+b`

`1 = 7(4) + b`
`b = -27`

`y = 7x - 27` therefore has the points `(5,8)` and `(4,1)`. You can find them here:

graph{7x -27 [-5.67, 14.33, -1.34, 8.66]}