angle AEB and angle CED are vertical angles, this means they equal each other, therefore we set their values as an equation and solve:
5x-10=3x+40
Subtract 3x to both sides
2x-10=40
Add 10 to both sides
2x=50
Divide both sides by 2
x=25
After we have gotten the value of x we can plug it in into the equation of angle AEB:
5x-10
Substitute x by 25
5(25)-10
Distribute
125-10
Substract
115
The measurement of angle AEB is 115
Hope it helped!, have a great day.