Question

Rationalize the denominator of 7+3√2​

Answer 1

31

Explanation:

To rationalise 7 + 3
`√(2)` , multiply by its conjugate

The conjugate of 7 + 3
`√(2)` is 7 - 3
`√(2)` , then

(7 + 3
`√(2)`)(7 - 3
`√(2)`) ← expand using FOIL

= 49 - 21
`√(2)` - 21
`√(2)` - (3
`√(2)`)²

= 49 - 18

= 31