the perimeter of a triangle is 51 centimeters, the longest side is 1 centimeter less than the sum of the other two sides. twice the shortest is 11 centimeters less than the longest side. find the lengths of each side of the triangle.

Answer 1

L=S1+S2-1
2*S1+11=L
L+S1+S2=51

rearranging these
S1+S2-L=1
2S1 -L=-11
S2+S2+L=51

add the two last equations
2S1+S2=40
subtract the first from the second
S1-S2=-12
add these two equations
3S1=28
S1=7

can you take if from here?

Answer 2

... add the two last eq.
3S1+S2=28
...
4S1=28

Answer 3

Thanks. I typoed and did not catch it.