SOLUTION: how do you find the b in y=mx+b

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Question 238193: how do you find the b in y=mx+b
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
the standard form is y = mx + b where m is the slope and b is the y-intercept.

assume you are given the slope and one point on the line.

let the slope = 2

let the point = (3,5)

the standard form of y = mx + b becomes y = 2x + b

now you take the point (x,y) = (3,5) that is on the line (has to be on the line) and replace x and y in the equation with it.

the equation becomes 5 = 2*3 + b

then you solve for b.

in this case b = 5-1 = -1

your equation becomes y = 2x - 1

graph of that equation looks like:

graph+%28400%2C400%2C-5%2C5%2C-5%2C5%2C2x-1%29

b is the y intercept which is the value of y when x = 0 which is -1.

the graph confirms that.

the slope is 2 which means that everytime x increases 1 unit, y increases 2 units.

that can be seen on the graph as well.

when x = 0, y = -1.

when x = 1, y = 1

when = 2, y = 3

etc.