Answer:
- as written: -1/2
- with parentheses: 3/4
Explanation:
The expression you have written is evaluated as ...
1 + (5/10) -2 = 1 + 0.5 - 2 = 1.5 -2 = -0.5 = -1/2
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If you add parentheses around everything left and right of the division symbol, it evaluates to ...
(1 +5)/(10 -2) = 6/8 = 3/4