Question

Which expressions are equivalent to the one below ? check all that apply :)

21^x/3^x

A- 7
B- (21-3)^x
C- 3^x
D- 7^x*3^x/3^x
E- (21/3)^x
D- 7^x

Answer 1

its b and e

Explanation:

Answer 2

Option D and E are equivalent to the given expression.

Explanation:

Given :
`(21^x)/(3^x)`

Solution:

`(21^x)/(3^x)`

Using identity :
`(a^x)/(b^x) = ((a)/(b))^x`

`((21)/(3))^x` -- Option E

Now this can be written as
`21^x = 7^x * 3^x`

Identity :
`a^x * b^x = (a \cdot b)^x`

`(7^x * 3^x)/(3^x)` -- Option D

`(7)^x` -- Option D

Thus Option D and E are equivalent to the given expression.