Question

Which statement is true about the difference 2 square root of 7 − square root of 28?

It is rational and equal to −2.
It is rational and equal to 0.
It is irrational and equal to −2square root of 7.
It is irrational and equal to square root of 7.

@DanJS

Answer 1

this?
\[\large 2\sqrt{7}-\sqrt{28}\]

Answer 2

yes

Answer 3

you cant simplify the first 2root7, the root28 you can though...

Answer 4

yes is it square root of 7 x square root of 2 and square root of 2
then its 4square root of 7 ???

Answer 5

28=4*7
root 4 is 2, so the root28 goes to 2root7
\[\sqrt{28}=\sqrt{4*7}=\sqrt{4}\sqrt{7}=2\sqrt{7}\]

\[2\sqrt{7}-\sqrt{28}=2\sqrt{7}-2\sqrt{7}=0\]

Answer 6

oh ok

Answer 7

i must have made a mistake somewhere ....thank you :)

Answer 8

welcome