Question 136436: Find an equation of the line containing the given pair of points. Express the answer in the form of y=my+b.
(-3, 5) and (2, -5)
HELP please
Answer by algebrapro18(249)   (Show Source):
You can put this solution on YOUR website! Well first we need to find the slope of the line between those two points. To do that we use the slope formula which is:
m = (y2-y1)/(x2-x1) where
x1 = -3
y1 = 5
x2 = 2
y2 = -5
so plugging in those numbers we get:
m = (y2-y1)/(x2-x1)
m = (-5-5)/(2-(-3))
m = -10/5
m = -2
Now we can find the slope intercept form of a line in two ways:
Method 1: Solve y = mx+b for b
Since we know that y=mx+b and we have numbers for y,m, and x we can plug those into the formula and solve for b.
y = mx + b
-5 = -2(2) + b
-5 = -4 + b
-1 = b
now plugging in your m and b values into the y=mx+b gives you the equation of the line. y = -2x - 1
Method 2: use the point slope formula and solve for y.
the is another formula that you might not have learned yet, its the point slope formula:
y-y1=m(x-x1) where
x1 = -3
y1 = 5
m = -2
now plugging in you get:
y-5 = -2(x-(-3))
y-5 = -2(x+3)
y-5 = -2x-6
y = -2x - 1
So the equation of the line though the two given points is y = -2x-1.
|
|
|
