Question

On dividing both the numerator and the denominator of 20a^2b/5ab^2 by ? The result is 4a/b

Answer 1

5ab is the correct answer

Answer 2

Answer:

$5ab$

Step-by-step explanation:

Given rational expression,

$\frac{20a^2b}{5ab^2}$

Let x be the expression by which on dividing both the numerator and the denominator the result is $\frac{4a}{b}$

That is,

$\frac{\frac{20a^2b}{x}}{\frac{5ab^2}{x}}=\frac{4a}{b}$

By comparing numerators,

$\frac{20a^2b}{x}=4a$

$20a^2b=4ax$     ( By cross multiplication )

$\implies x = \frac{20a^2b}{4a}=5a^{2-1}b^2=5ab$

Note : We can get the answer by comparing denominators.