Insert the corresponding expression:
5−8×56=
Let's simplify the expression 5−8×56 using the rules of exponents.
- Step 1: Apply the rule for multiplying powers with the same base. According to this rule, when multiplying like bases, we add the exponents:
5−8×56=5−8+6
- Step 2: Calculate the sum of the exponents:
−8+6=−2.
- Step 3: Write the simplified expression:
5−2.
- Step 4: Relate the expression to the given choices:
The simplified expression 5−2 corresponds to choice 1. Additionally, rewriting a negative exponent using the fraction format gives:
5−2=521, which matches choice 2.
Thus, both choices 'a: 5−2' and 'b: 521' are correct.
Therefore, according to the given answer choice, a'+b' are correct.