Question

the answer is 3/28 .. pls explain with method how it came..

Answer 1

Answer:

49= 7²

21= 3×7

Substitute these values in question.

You get

$\frac{ ({7})^{ - 5} \times {7}^{2} \times 7 \times 3 } { {7}^{2} \times {2}^{2} \times {7}^{ - 3} } = 3 \times {7}^{ - 3} = \frac{3}{343}$

Formula used:

$\frac{1}{ {a}^{m} } = {a}^{ - m}$