Which statement is true about the difference 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.

Question

Which statement is true about the difference 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.

anonymous · Answer

@jinxhead20 , @e.mccormick , @magepker728 , @mathmale , @Mokeira , @Burningitdown

one098 · Answer

$$\sqrt{7}-\sqrt{28}$$ What are the square roots of each?

anonymous · Answer

0 and 14?

mokeira · Answer

$$\sqrt{28}=\sqrt{7\times4}=2\sqrt{7}$$
therefore
$$\sqrt{7}-2\sqrt{7}=?$$

mokeira · Answer

imagine it this way b-2b wher b is sqrt 7

anonymous · Answer

wouldn't that be rational and equal to 0 ?

anonymous · Answer

@Mokeira

mokeira · Answer

it is equal to $$-\sqrt{7}$$ but i do not see this in choices