Question

The first side of a triangle is 3 inches shorter than the second side, and 2 inches longer than the third side. How long is each side, if the triangle has a perimeter of 28 inches?

Answer 1

f=s-3
f=t+2
f+t+s=28

putting in matrix form
f -s +0t=-3
f+0s-t=2
f+s+t=28
add 1 and 3
2f+t=25
now add that to 2)
3f=27
f=27/3
then f=9
then put that in 1 and solve for s, and finally solve for t in equation 2

Answer 2

2nd side = X in.
1st. side = x - 3 in.
3rd side = (x-3) - 2 = x - 5 in.

x + (x-3) + (x-5) = 28.
X = 12 in.
x-3 = 12 - 3 = 9 in.
x - 5 = 12 - 5 = 7 in.