Negative powers
The question
Mia wrote x⁷ · x⁻³ = x²¹. Which is correct?
Mia wrote x⁷ · x⁻³ = x²¹. Which is correct?
x⁷ · x⁻³
x⁷ · x⁻³=x^(7 − 3)
x⁷ · x⁻³=x^(7 − 3)
x⁷ · x⁻³=x⁴
x⁷ · x⁻³=x⁴
they wrote:x²¹
- Do the step yourself first, then compare with their line.
- On your own, writing every step: x⁷ · x⁻³ becomes x^(7 − 3).
- Tidy that up and it is x⁴.
- Now compare. They wrote x²¹, and the two powers were multiplied instead of added — so the correct answer is x⁴.
How it works.
- 01
Do the step yourself first, then compare with their line.
- 02
On your own, writing every step: x⁷ · x⁻³ becomes x^(7 − 3).
- 03
Tidy that up and it is x⁴.
- 04
Now compare. They wrote x²¹, and the two powers were multiplied instead of added — so the correct answer is x⁴.