Answer:
My uncle is 78 years old.
Step-by-step explanation:
Let the age of your uncle be x.
400 - 2x = 244
Shift (-2x) to the other side and change it to (+2x).
400 = 244 + 2x
Shift (+244) to the other side and change it to (-244).
400 - 244 = 2x
Evaluate.
2x = 156
Find x.
x = 156 ÷ 2
x = 78
