Question 85 (a)

Evaluate
$\frac{7^8\times a^{10}{b}^7{c}^{12}}{7^6\times a^8{b}^4{c}^{12}}$

We have $\frac{7^8\times a^{10}{b}^7{c}^{12}}{7^6\times a^8{b}^4{c}^{12}}=\left(\frac{7^8}{7^6}\right)\times \left(\frac{a^{10}}{a^8}\right)\times \left(\frac{b^7}{b^4}\right)\times \left(\frac{c^{12}}{c^{12}}\right)=7^{8-6}\times a^{10-a}\times b^{7-4}\times c^{12-12}=7^2\times a^2\times b^3\times c^0=49a^2{b}^2$