Find the point at which the line joining the two points (-3, -5) and (7,5) cuts the y-axis.

Question

mertsj · Answer

First find the equation of the line:
1.  Find the slope
2.  Choose one of the points and plug into point-slope form
3.  Put the equation into slope-intercept form
4.  Identify the y-intercept which is the point where the line cuts the y-axis.

anonymous · Answer

Sorry, I'm not quite sure how to do that... Could you please teach me?

mertsj · Answer

The definition of slope is:
$$m = \frac{y _{2}-y _{1}}{x _{2}-x _{1}}$$

anonymous · Answer

So, m=5−-5
           -5−-3
?

mertsj · Answer

$$m=\frac{5-(-5)}{7-(-3)}=\frac{10}{10}=1$$

mertsj · Answer

Now choose one of the points and plug into:
$$y-y _{1}=m(x-x _{1})$$

anonymous · Answer

So, 10 - 7 = m(10 - -3) ?

mertsj · Answer

Choose ONE of the points and replace x_1 and y_1 with those coordinates.  Do not replace x and y

mertsj · Answer

Also we now know that m = 1 so replace m with 1

anonymous · Answer

Okay, so 5−7 = 1(-5−-3) ?

mertsj · Answer

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