Question

How do you write an equation of a line with (4, –4) and (9, –1)?

Answer 1

Equation of the line y = ax + b.

Explanation:

Find a and b.

Slope `a = (y_2 - y_1)/(x_2 - x_1)` `= (-1 - (-4))/(9 - 4) = 3/5`

Next, write that the line `y = 3/5x` passing at point `(4,-4)`:

`-4 = 3/5(4) + b -> b = - 4 - 12/5 = - 32/5`

Line equation: `y = 3/5x - 32/5`