Write the standard form of the equation of the line through the given point with the given slope.

Question

Given Points that it goes through: (1,2)

Slope: 7

 

I am having a lot of trouble on this topic and I have an upcoming quiz on this topic. I am hoping to get my grades up. Please help to the best of your ability. 

Answer 1

Use (y-y1)=m(x-x1) where m=slope and x1 and y1 given. In this case (1,2).  X1=1 and y1=2. Then plug in and combine like terms. Then it must be written in y=mx+b, where m is the slope which in this case is given as 7.

 

(y-2)=7(x-1)

Y-2=7x-7

y=7x-5

 

So y=7x-5 is in the form of y=mx+b, so that's your answer. Notice that the + sign is arbitrary, because sometimes it will be a negative number when you solve the formula (y-y1)=m(x-x1), as in this case.

 

b is what's called the y intercept, or where the line crosses the y axis. So this line crosses the y axis at -5.