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Question 134699: Given two points (-3,-2) and (4,-5) write the slope intercept form of the line. Again I need it solved by point slope form and then given the slope intercept form. I really need help!
y-y1=m(x-x1)
y=3/-7x+b
Found 2 solutions by stanbon, algebrapro18:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Given two points (-3,-2) and (4,-5) write the slope intercept form of the line. Again I need it solved by point slope form and then given the slope intercept form. I really need help!
y-y1=m(x-x1)
y=3/-7x+b
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Point-Slope Form Solution:
slope = (-5--2)/(4--3) = -3/7
y-y1 = (-3/7) (x-x1)
y--2 = (-3/7) (x--3)
y+2 = (-3/7)x - (9/7)
y = (-3/7)x -(9/7) - (14/7)
y = (-3/7)x -(23/7)
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Slope Intercept Form solution:
slope = (-5--2)/(4--3) = -3/7
You have an x, a y, and the slope, so solve for "b" in the form y= mx+b
-2 = (-3/7)(-3)+b
-2 = (9/7) + b
b = -14/7 -(9/7)
b = -23/7
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y = (-3/7)x - (23/7)
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Cheers,
Stan H.
Answer by algebrapro18(249) (Show Source):
You can put this solution on YOUR website! Well first we need to find the slope between those two points. Remember the slope of the line is found using this formula:
m = y2-y1/x2-x1 where, in this case:
x1 = -3
y1 = -2
x2 = 4
y2 = -5
so now we find the slope:
m = -5 -(-2) / 4-(-3)
m = -5 + 2 / 4+3
m = -3 / 7
now since we have a point(doesn't matter which of the given points you use) and the slope we use the point slope formula which is:
y-y1 = m(x-x1)
Now its just a matter of plug and chug to get the point-slop form of that line:
y - (-2) = -3/7(x-(-3))
y + 2 = -3/7(x + 3)
Now we just solve for y to get the slope-interecept form of the line:
y = -3/7x - 9/7 - 2
y = -3/7x -23/7
Now to check to make sure the math is right(I do make mistakes sometimes)
x = -3
y = -2
-2 = -3/7(-3) -23/7
-2 = 9/7 - 23/7
-2 = -14/7
-2 = -2
this point checks out now lets check the next one
x = 4
y = -5
-5 = -3/7(4) -23/7
-5 = -12/7 - 23/7
-5 = -35/7
-5 = -5
this point checks out also so you get your final answer of y = -3/7x - 23/7
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