Question

Help me with this question

Answer 1

First we simplify
`√(12)` :

`√(12)` =
`√(4)` ×
`√(3)`

This can be simplified further, because
`√(4)` is just 2:

`√(4)` ×
`√(3)` = 2
`√(3)`

So
`√(12)` = 2
`√(3)`

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Now we write 2
`√(3)` instead of
`√(12)` in the question:

2
`√(3)` ( -1 +
`√(5)`)

We solve this by multiplying 2
`√(3)` by the numbers in the brackets:

2
`√(3)` ( -1 +
`√(5)`) = -2
`√(3)` + 2
`√(15)`

(Explanation: 2
`√(3)` × -1 = -2
`√(3)` , and 2
`√(3)` ×
`√(5)` = 2
`√(15)` because the numbers inside of the squares are multiplied by each other - So the 3 times the 5 equals 15)

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Answer:

-2
`√(3)` + 2
`√(15)`

(Option B)