The greatest possible error is one half of the measuring unit you're using.
Multiply the unit you use by 1/2:

The greatest possible error will be
1/8 inch.
(5x10 to the 4th power) + (2x10 to the 3rd power) + (6x 10) + (7x1)
Answer:
4. 61
5. approximately 43
6. 120
Step-by-step explanation:
4. 80 + 39 = 119
180 - 119 = 61
5. 7x - 10 = 90
+10 +10
7x = 100
divide by 7
x = 14.3
3 times 14.3 = 42.9
6. 70 + 50 = 120
180 - 120 = 60
180 - 60 = 120