This is because if you do the algebra which is 4x+3+2x+8+3x-10=136, x=15. Now that you have 15 you plug it into each sides x value. First, 4x+3= 4*15+3=63
Second, 2x+8=30+8=38
Lastly, 3x-10=45-10=35
So, as you can see here 35 is the lowest value which means the side (3x-10) is the shortest.
