Question

Find the value
i) $(-7{)}^{12}÷(-7{)}^{12}$
ii) $7^5÷7^3$

• A. i) $1$ii) $49$
  
• B. i) $0$ii) $49$
• C. i) $0$ii) $7$
• D. i) $1$ii) $7$

Answer 1

The correct option is A i) $1$

ii) $49$

(1) $(-7{)}^{12}÷(-7{)}^{12}$

$=(-7{)}^{12}\times \frac{1}{(-7{)}^{12}}$

$=\frac{(-7{)}^{12}}{(-7{)}^{12}}$

Now apply law of exponents, $\frac{x^m}{x^n}=x^{m-n}$

So, the expression is

$=(-7{)}^{12-12}$

$=(-7{)}^0=1$

(2) $7^5÷7^3$

$=7^5\times \frac{1}{7^3}$

$=\frac{7^5}{7^3}$

Now apply law of exponents, $\frac{x^m}{x^n}=x^{m-n}$

So, the expression is

$=7^{5-3}$

$=7^2$

$=49$