Does the negative apply before or after an exponent
Solution 1:
Neither of you is right - or at least, you are both half right.. $$-8^0=-8^{1/2-1/2}=\frac{-8^{1/2}}{-8^{1/2}}$$ Now we compromise so that everyone gets an equal chance: $$\frac{-2\sqrt 2}{2\sqrt 2 i}={-1\over i}=i$$ So the answer is $i$. The imaginary unit. The enigma of the conundrums. The unspeakable number.
I have divulged this information at great risk to our agents in the field. Please use this remarkable knowledge with discretion, and always remember: use more parentheses.
Solution 2:
Exponents take precedence over multiplication. Your friend is wrong.
Solution 3:
In general, operations are done in this order:
- Brackets
- Exponents
- Division and Multiplication
- Addition and Subtraction
For example, $10 + 0 \times 5$ isn't read as "$10 + 0 = 10$, $10 \times 5 = 50$", it's read as "$0 \times 5 = 0$, $10 + 0 = 10$".
Your example is slightly trickier as you have to recognize what the minus sign really means. "$-n$" is essentially shorthand for $0-n$, and realizing that makes the answer clear.
Your equation is "really" $0-8^0$. Looking at the list from earlier, we see that exponents are done before subtraction, so that step comes next. $0-8^0$ becomes $0-1$, which we write as $-1$. You are correct.
Really, though, the question is less than ideal. Writing it as $-(8^0)$, as you say, would clear up a lot of problems. It's very easy to misread or misunderstand a problem and steps clearly were never taken to avoid that here.
Solution 4:
You are correct: without parenthesis around the (−8), the formula −80 is equivalent to (−1) * (80).
You trying to determine whether the equation, −80 = x, like −23 = x, will result in x being positive or negative. 1 − 23 = −7 can be written as 1 + −23 = −7 or 1 + (−1) * (23) = 7. Clearly the negative addition of terms is separate from the result of the exponent.