SOLUTION: I have 3 parts to my question: A person cuts a board into two pieces that are equal in length. The first piece is 3 times the length of the person's forearm minus 1 inch. The

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: I have 3 parts to my question: A person cuts a board into two pieces that are equal in length. The first piece is 3 times the length of the person's forearm minus 1 inch. The       Log On


   



Question 144674: I have 3 parts to my question:
A person cuts a board into two pieces that are equal in length. The first piece is 3 times the length of the person's forearm minus 1 inch. The second piece is 5 times the length of the person's forearm plus 15 inches.
I have to
1.) Construct a linear equation that represents this situation using x as the variable for the person's forearm.
2) Solve the linear equation algebraically and graphically to find the length of the person's forearm.
3.) Discuss whether or not my answer is reasonable.
So, here is what I have come up with thus far...
x=3x-1+5x+15
x=8x+14 (combine like terms)
x=8x-8x+14
x-8x=14
-7x=14
(Divided by -7)
x=-2
And this is where I get lost. If my answer is correct I then substituted my answer of -2 into each equation:
3x-1=x
3(-2)-1=x
-6-1=x
-7=x
5x+15=x
5(-2)+15=x
-10+15=x
5=x
I am confused as to how to graph my equation?

Answer by vleith(2983) About Me  (Show Source):
You can put this solution on YOUR website!
Let the two pieces of wood be y and z. Let x be the forearm
The system of equations is as :
y+=+3x+-1
z+=+5x+%2B+15

the graph is
graph%28600%2C+400%2C+-10%2C+10+%2C+-30%2C+10%2C+3x-1%2C+5x+%2B+15%29


Is the answer reasonable? No. The value where to two plots meet yields x=-8
No one has a forearm that is negative in size.