the length of BE = 3x-24
Length of ED = x+10
so 3x-24 = x+10
subtract x from each side to get
2x-24=10
now add 24 to each side to get
2x=10+24, which is 2x=34
now divide both sides by 2 to get x
34/2 = 17 so X=17
now sub that for x into the formula
3x17-24 = 27