Question 623677
Dear All,

I wish if you could help me understand below, please?

The problem says: Line X has a slope of 3. The line passes through Point X at (-2,-1) and also passes through Point Z., which has an x-coordinate of 0. What are the coordinates of Point Z?

So I guess that I have to substitute the given values in the formula m=Y2-y1 / X2-X1 (sorry I could not find the small 2s and 1s in my keyboard). So I got: 3= -1-y/-2-0 then 3= -1-y / -2 and after that I am stuck. I do not know how to find the Y value.

Many thanks for your help.
Ilda


What you're trying to find is {{{y[2]}}}, the 2nd y-coordinate of the line


What you have is: {{{3 = (- 1 - y[2])/(- 2)}}}


{{{- 6 = - 1 - y[2]}}} ----- Cross-multiplying


{{{- 6 + 1 = - y[2]}}}


{{{- 5 = - y[2]}}}


{{{(- 5)/- 1 = y[2]}}}


{{{5 = y[2]}}}


Since {{{y[2]}}} = 5, then coordinate point of Z  = ({{{highlight_green(0)}}},{{{highlight_green(5)}}})


Note:
The fact that Z's x-coordinate is 0 signifies that Z is the y-intercept. Therefore, the general form of the equation of a line (y = mx + b) should be used to solve for b, which would give the y-coordinate of Z. This is much easier, but only because itw's given that Z's x-coordinate is 0.


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