the formula you can use is
y - y1 = m(x - x1)
plug the y value you are given into y1 and the x value you are given into x1. m is for your slope value. after you plug in the known values, solve. your final answer should be in standard form which is
Ax + By = C
your answer should not contain any fractions and your Ax value cannot be a negative value, By and C can be negative though.
hope this helps :)