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

Question

asked Jul 25, 2018 70.2k views

2 Answers

Josejuan · Answer 1 · 2018-07-30T21:30:12+0000

Answer:

5ab

Explanation:

Given rational expression,

(20a^2b)/(5ab^2)

Let x be the expression by which on dividing both the numerator and the denominator the result is
(4a)/(b)

That is,

((20a^2b)/(x))/((5ab^2)/(x))=(4a)/(b)

By comparing numerators,

(20a^2b)/(x)=4a

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

$\implies x = (20a^2b)/(4a)=5a^(2-1)b^2=5ab$

Note : We can get the answer by comparing denominators.