Question 84513
Find the y-intercept.
{{{-x+3y=15}}}
If you put this equation into y=mx+b form, you can just read off the y-intercept, since that is the 'b' term:
{{{3y=x+15}}}
{{{y=(x/3)+5}}}
So the y intercept is 5.
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Determine which two equations represent perpendicular lines.
a. y=4/7x-3     b. y=3x-4/7    c. y=-1/3x+4/7  d. y=1/3x-4/7.
Perpindicular lines have slopes which are negative reciprocals of each other. It is easy to read off the slopes of these 4 lines, since they are all already in y=mx+b form, and m is the slope.
So the answer is (b) and (c), since -1/3 is the negative reciprocal of 3.
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I wil let you try the last 2 parts!
Good Luck,
tutor_paul@yahoo.com