How do you write an equation of a line given (9,-5), m=-1/3?

1 Answer
Aug 29, 2017

y=13x2

Explanation:

Let the given point be P1(x1,y1)=(9,5)

Let the gradient be m=13

Using the standardised form y1=mx1+c

Where c is a constant

Then by substitution: 5=(13)(9)+c

but 13×9=3 giving:

5=3+c

Add 3 to both sides

5=3+cdddd5+3=3+3+c

ddddddddddddddddd2d=dddd0d+c

Thus c=2 so the finished equation is:

y=13x2