How do i find the equation for (3,12) and (1,4)? http://prntscr.com/33ltsw

Question

anonymous · Answer

Apply the formula
$$
\frac{y-y_1}{x-x_1}=\frac{y_1-y_2}{x_1-x_2}
$$

anonymous · Answer

im trying but i'm not to good at this is the answer 4

anonymous · Answer

$$

\frac{y-12}{x-3}=\frac{12-4}{3-1}=4
$$

anonymous · Answer

btw how would i know which is like y2 and like y1 ? does it make a difference

anonymous · Answer

$$
y-12=4(x-3)=4 x-12\
y=4 x
$$

anonymous · Answer

No

anonymous · Answer

so it doesnt matter which one i pick as y1 or y2?

anonymous · Answer

The equation is y=4x

anonymous · Answer

No

anonymous · Answer

thanks for helping :) really helps

the_fizicx99 · Answer

1. It doesn't make a difference because if it does result in being negative the rules for positive and negatives will regulate the answer

2. That's a bit unnecessary, you could've just used M = y2-y1/x2-x1
and y-y1=m(x-x1)

anonymous · Answer

thanks to both of you guys :)

the_fizicx99 · Answer

yw