SOLUTION: Need help, I cant remenber where to start and how to make the formula work. A piece of wire 83 centimeters long must be into 3 pieces. Two pieces will be the same length, and th

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Question 98222: Need help, I cant remenber where to start and how to make the formula work.
A piece of wire 83 centimeters long must be into 3 pieces. Two pieces will be the same length, and the the third will be 7 centimeters less than twicw the others. Find the length of each wire.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=length of 1st segment (and length of second one since they are equal), and y=length of 3rd segment


Since the 3rd one is "7 centimeters less than twicw the others", then we have the equation


y=2x-7

Now add up the segments to get 83


x%2Bx%2B2x-7=83 Start with the given equation


4x-7=83 Combine like terms on the left side


4x=83%2B7Add 7 to both sides


4x=90 Combine like terms on the right side


x=%2890%29%2F%284%29 Divide both sides by 4 to isolate x



x=45+%2F+2 Reduce

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Answer:
So our answer is x=45+%2F+2 (which is x=22.5 in decimal form)


So the first two segments are 22.5 cm

Now plug in x=22.5 to find the 3rd segment


y=2%2822.5%29-7 Plug in x=22.5


y=38 Evaluate


So the 3rd segment is 38 cm


Check:

Simply add the 3 segments to find the total length

22.5%2B22.5%2B38=83

Since the segments add to 83, our answer is verified.