Question

What's the equation of the line passing through (-1,-9) and (3,11) , in the form y=mx+c?

Answer 1

that points lie on the line .. plug them in the equation

-9=-m+c
11=3m+c

solve for m and c

Answer 2

Can also find m first using slope formula
\[m=\frac{y_2-y_1}{x_2-x_1} \space .\]
Then use one point and y=mx+c to solve for c.