keeping in mind that perpendicular lines have <u>negative reciprocal</u> slopes, let's find the slope of 3x + 4y = 9, by simply putting it in slope-intercept form.
![\bf 3x+4y=9\implies 4y=-3x+9\implies y=-\cfrac{3x+9}{4}\implies y=\stackrel{slope}{-\cfrac{3}{4}}x+\cfrac{9}{4} \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ \stackrel{\textit{perpendicular lines have \underline{negative reciprocal} slopes}} {\stackrel{slope}{-\cfrac{3}{4}}\qquad \qquad \qquad \stackrel{reciprocal}{-\cfrac{4}{3}}\qquad \stackrel{negative~reciprocal}{+\cfrac{4}{3}}\implies \cfrac{4}{3}}](https://tex.z-dn.net/?f=%20%5Cbf%203x%2B4y%3D9%5Cimplies%204y%3D-3x%2B9%5Cimplies%20y%3D-%5Ccfrac%7B3x%2B9%7D%7B4%7D%5Cimplies%20y%3D%5Cstackrel%7Bslope%7D%7B-%5Ccfrac%7B3%7D%7B4%7D%7Dx%2B%5Ccfrac%7B9%7D%7B4%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20%5Crule%7B34em%7D%7B0.25pt%7D%5C%5C%5C%5C%20%5Cstackrel%7B%5Ctextit%7Bperpendicular%20lines%20have%20%5Cunderline%7Bnegative%20reciprocal%7D%20slopes%7D%7D%20%7B%5Cstackrel%7Bslope%7D%7B-%5Ccfrac%7B3%7D%7B4%7D%7D%5Cqquad%20%5Cqquad%20%5Cqquad%20%5Cstackrel%7Breciprocal%7D%7B-%5Ccfrac%7B4%7D%7B3%7D%7D%5Cqquad%20%5Cstackrel%7Bnegative~reciprocal%7D%7B%2B%5Ccfrac%7B4%7D%7B3%7D%7D%5Cimplies%20%5Ccfrac%7B4%7D%7B3%7D%7D%20)
so we're really looking for the equation of a line whose slope is 4/3 and runs through 8, -4.

I made a probability tree. Pls. see attachment.
Based on the probability tree I made, below are the probabilities
Probability of a student accepted at both Dartmouth and Harvard is:
50% x 40% = 20%
Probability of a student accepted at Dartmouth but not Harvard is:
50% x 60% = 30%
Probability of a student not accepted at Dartmouth but accepted in Harvard is:
50% x 20% = 10%
Probability of a student not accepted in both schools is:
50% x 80% = 40%
As you can see, these probabilities total 100%
Answer:
Okay so number 3 is either undefined or Zero. I always forget which is which.
Step-by-step explanation:
But for 1 and 2 use your solution m=rise/run. Or you could count the ways down, like say, for number 1 it runs over 3 from a point and goes up till the next point. I hope this helps.