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put this solution on YOUR website!The first thing to do is to assign variables for the sides of the triangle. I am going to call them X, Y, and Z. The first side, X, is 7cm shorter than twice the second side, Y. Written as an equation, this is
. Then, you know that the third side, Z, is 4cm longer than the first side. WRite as an equation, this is
. The perimeter, which is the sides added together, is 80. So,
.
To solve this, you will need to figure out a way to get X + Y + Z = 80 to have only 1 variable in it. Since you know that Z = X + 4, you can plug X + 4 in for Z in that equation. Now you have
. For the first equation we wrote, solve for Y, which makes the equation
. Now plug this in for Y in the longer equation, which changes it to
. To solve the equation, add like terms, which changes the equation to
. Move the 11 to the right side of the equation, which is
. Solve for X (X = 23). To figure out Y and Z, simply plug 23 in for X in the original equations.
; Y=30.
; Z=27.
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