write in y=mx+b form

Question

m=3/7;(7,-5)

Answer 1

The trick to problems like this is finding b.  We already know that the formula will be y = (3/7) x  + b because we were given 3/7 as the slope.  Since we know the point (7,-5) is on the line, we have a known x and y to plug into the formula thus:

 

-5 = (3/7)(7) + b

 

Now solve for b using basic algebra:

 

-5 = 3 + b (fraction multiplication)

-8 = b (subtracting 3 from both sides)

 

The formula, then, is

 

y = (3/7) x -8