sqrt of 63-2sqrt of 28 +5 sqrt7?

Question

I am getting confused on what to do with the 2 sqrt of 28 part please help/explain thanks

Answer 1

sqrt(63)=sqrt(9*7)=sqrt(9)*sqrt(*7)=3 sqrt(7),

now do the same sort of thing with sqrt(28).

Answer 2

ok now leave thesqrt 63 alone
take the 2 sqrt of 28
now 28 can be broken
down as 7 * 4
and u know the sqrt of 4 is 2
therefore sqrt of 28
can be written as
4sqrt 7
now u have
63-4 sqrt7 + 5 sqrt 7

simplify it
u have
sqrt63-9sqrt 7

sqrt 63 is
sqrt of 9 * 3
and u know sqrt of 9 =3
therefore sqrt of 63 = 3 sqrt of 3
so now u can write the whole thing as
3sqrt 3 - 9 sqrt 7

at this point if u want to go another step ahead.. u can take 3 common and write it as
3(sqrt 3 - 3 sqrt 7)
but then agin u dont have to

Answer 3

2sqrt is just the sqrt. lets say ( is now the sqrt sign. you can take (4 times the (7 and get "2(7" which is equal to the sqrt of 28. so you now have 63-2(7+5(7. next is 63-7(7 which will give you 63-7, which we all know is 56!

Answer 4

2sqrt of 28
means
two times the square root of 28
2*SQRT(28)

So, find the SQRT(28), then multiply it by 2.

note:
if you can factor the number in the root, you can "distribute" the root:

28 = 7*4
SQRT(28) = SQRT(4)*SQRT(7)
SQRT(4) = 2
(I know that we should say +/- "plus or minus" but when the square root is used as a function in maths, we take the positive value by convention -- a function can only have one defined answer).

Anyways:
2*SQRT(28) = 2*2*SQRT(7) = 4*SQRT(7)


SQRT(63) = SQRT(9)*SQRT(7) = 3*SQRT(7)

You will end up with a sum of terms that all contain SQRT(7). You can add them the same way you can add apples:

3 apples - 4 apples + 5 appes = 4 apples.
3*SQRT(7) - 4*SQRT(7) + 5*SQRT(7) =

Answer 5

= 3.√7 - 2 x 2.√7 + 5√7
= 8.√7 - 4.√7
= 4.√7

Answer 6

This looks to be just a simplification problem.

The first part can be broken down to sqrt9*sqrt7=3sqrt7.
The second part can be broken down to sqrt4*sqrt7=
(2*2)sqrt7. The initial two stays in front to be multiplied by the sqrt4 which is two, thus giving you 4sqrt7.
The third part stays as it is, because 7 is a prime number, thus cannot be factored any lower.

The final answer then is: 3sqrt7 - 4sqrt7 + 5sqrt7=4sqrt7.

Sudhi_kandi's answer above is incorrect, as there is a math error converting sqrt63---that whole section messed up the rest of the answer.