Robot starts to overturn when reaching to pick up a load

[crystallizedyogurt]

Homework Statement

The robot has an extendable arm that weighs 25 lb and picks up a 125-lb load at point B. If the robot starts to overturn when the moment at point A is 100 ft*lb, how far out (x) can the are extend

Relevant Equations

M = Force * Arm

M robot = (125-25)lb* 1 ft = 25 lb*ft
M arm = 25 lb * (x/2 -1 )
M load = 125 lb * (x-1)
Mtotal =. 100 + 12.5 x -25 + 125 x -125 = 100
X = 1.09 ft
but the correct answer is 1.82 feet, why?

 

[haruspex]

Mtotal =. 100 + 12.5 x -25 + 125 x -125 = 100

What is the "100" on the left?
What, exactly, do you think is intended by "the moment at point A" in the question?

 

[Lnewqban]

Welcome, @crystallizedyogurt !

Are you still interested on this problem?