Question

Find the lowest rationalising
factor of 15-3√2

Answer 1

15-root 2 = 3(5-root 2 )

= 3(5-root 2 ) (5 - root 2 )

= 3 [ 5 ^2 - root 2 ^2 ]

= 3 × (25-2)

= 3 × 23

= 69

The lowest rationalising factor is 69 . Ans

Hope it may help u !!

Answer 2

15−3√2

step one : takinɡ out factor 3 out

3(5−√2)

then rationalizinɡ the numbers in bracket

3(5−√2)(5+√2)

then solvinɡ further

3[5²−(√2)²]

now

3(25−2)

3(23)

69.

The answer to the problem is 69

BUT

The answer of the question asked is Rationalizinɡ factor of 15−3√2 is 5+√2 bcoz we rationalized the ɡiven number only when we have this above number 5+√2.

Hope it helps you !!