Question

Question 2(iv)
Simplify and express the result in power notation with positive exponent:

$(3^{-7}÷3^{-10})\times 3^{-5}$

Answer 1

$(3^{-7}÷3^{-10})\times 3^{-5}=3^{-7-(-10)}\times 3^{-5}[\because a^m÷a^n=a^{m-n}]=3^{-7÷10}\times 3^{-5}=3^3\times 3^{-5}=3^{3+(-5)}[\because a^m\times a^n=a^{m+n}]=3^{-2}=\frac{1}{3^2}[\because a^{-m}=\frac{1}{a^m}]$