SOLUTION: Write an equation of the line that passes through the given points . 1. (-3,-3), (2,1) Give the answer with the appropriate unit of measure. 2. -3 1/3 miles + 1 2/3 mil

Algebra ->  Equations -> SOLUTION: Write an equation of the line that passes through the given points . 1. (-3,-3), (2,1) Give the answer with the appropriate unit of measure. 2. -3 1/3 miles + 1 2/3 mil      Log On


   

Question 891867: Write an equation of the line that passes through the given points .
1. (-3,-3), (2,1)

Give the answer with the appropriate unit of measure.
2. -3 1/3 miles + 1 2/3 miles
Found 2 solutions by josmiceli, JulietG:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Use the general point-slope formula:
( -3,-3 ) , ( 2,1 )

+%28+y+%2B+3+%29+%2F+%28+x+%2B+3+%29+=+%28+1+%2B+3+%29+%2F+%28+2+%2B+3+%29+
++%28+y+%2B+3+%29+%2F+%28+x+%2B+3+%29+=+4+%2F+5+
+y+%2B+3+=+%28+4%2F5%29%2A%28+x+%2B+3+%29+
+y+%2B+3+=+%28+4%2F5+%29%2Ax+%2B+12%2F5+
+y+=+%28+4%2F5+%29%2Ax+%2B+12%2F5+-+15%2F5+
+y+=+%28+4%2F5+%29%2Ax+-+3%2F5+
------------------------
check:
( -3,-3 )
+y+=+%28+4%2F5+%29%2Ax+-+3%2F5+
+-3+=+%28+4%2F5+%29%2A%28-3%29+-+3%2F5+
+-3+=+-12%2F5+-+3%2F5+
+-3+=+-15%2F5+
+-3+=+-3+
OK
You can check the other point

Answer by JulietG(1812) About Me  (Show Source):
You can put this solution on YOUR website!
The equation of a line: y=mx + b
m is the slope
b is the y-intercept
M = %28y2-y1%29%2F%28x2-x1%29 where x,y are the points given
In this case,
1 - -3 over 2 - -3
or m=4%2F5
Now you have the m
y = 4%2F5x + b
Using one of your points (2,1), we can plug it in to the formula to get:
1 = 4%2F5*2+b
Subtract 8%2F5from each side
=3%2F5=b
Now go back to the equation y=4%2F5x+b and add in the b
y=4%2F5x-3%2F5
.
Question #2:
-3 1/3 miles + 1 2/3 miles
-10%2F3miles + 5%2F3miles = -5%2F3miles, or -12%2F3miles