Slope is very tricky for me. I did this one like the book shows and I get the answer of y = 3x + 15 but then do it based off my notes and get y = 3x - 10 so I am doing this wrong I think. Can someone show me a good method for solving?

- Thread starter josh123
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Slope is very tricky for me. I did this one like the book shows and I get the answer of y = 3x + 15 but then do it based off my notes and get y = 3x - 10 so I am doing this wrong I think. Can someone show me a good method for solving?

There is one formula to use when you know the slope, m. Well it comes in two "flavors" but it is the same.

y=mx+c if you know what the y intercept is (that is the form your "answer" is in, but you have m=3 so it can't be correct. m=-4)

or

(y-a)=m(x-b) when you know that it goes thru P(b,a)

In both the slope is m.

Since they tell you the point and the slope (P(3,2) & -4) the second is the one you want.

Just solve

(y-2)=-4(x-3)

for y.