Question 107478This question is from textbook Introductory Algebra
: Solve by any appropriate method.(Substitution or Elimination, I prefer Elimination). L1-(-4,4)and(2,-2) L2-(1,1) and (-3,3). I don't even know where to begin and our teacher and not provided any examples for this type of problem. He doesn't use the book much and I have tried to find examples and am unsuccessful.
This question is from textbook Introductory Algebra
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! Solve by any appropriate method.(Substitution or Elimination, I prefer Elimination).
L1-(-4,4)and(2,-2)
Y=mx+b
Need to find m and b.
slope = [4--2]/[-4-2] = 6/-6= -1
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substitute x=2, y=-2, m=-1 to solve for "b":
-2 = -1*-2 + b
-2 = 2 + b
b = -4
EQUATION L1: y = -x-4
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L2-(1,1) and (-3,3).
m = [3-1]/[-3-1]= 2/-4 = -1/2
Substitute x=1, y=1, m=-1/2 to solve for "b":
1 = (-1/2)*1 + b
b = (3/2)
EQUATION: L2: y = (-1/2)x + (3/2)
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Solve the system:
Substitute y = -x-4 into L2 to get:
-x-4 = (-1/2)x + (3/2)
Add x to both sides to get:
-4 = (1/2)x + (3/2)
Subtract (3/2) from both sids to get:
-11/2 (1/2)x
x = -11
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Substitute into y = -x-4 to solve for "y":
y = -(-11)-4 = 7
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Solution for the system: x=-11, y=7
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Cheers,
Stan H.
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