Answer:
x = 20.
Step-by-step explanation:
1/2x + 40 = 50
1/2x + 40 - 40 = 50 - 40
1/2x = 10
1/2x * 2 = 10 * 2
x = 20
x=20
50-40= 10 and 10 x 2 = 20