Question

Here's an interesting question. It will blow your mind. Best of luck.

Answer 1

Hi ,

i ) √20 = √ 2×2×5 = 2√5

ii ) √40 = √ 2 × 2 × 10 = 2√10

iii ) √80 = √ 4 × 4 × 5 = 4√5

iv ) √10 + √20 + √40 - √5 - √80

= √10 + 2√5 + 2√10 - √5 - 4√5

= 3√10 - 3√5

= 3( √10 - √5 ) -----( 1 )

Now ,

15/( √10 + √20 + √40 - √5 - √80 )

= 15/[ 3( √10 - √5 )

= 5/( √10 - √5 )

Rationalize the denominator ,

= [5( √10 + √5 ) ]/[ ( √10 - √5 )( √10 + √5 ) ]

= [ 5( √10 + √5 ) ]/[ ( √10 )² - ( √5 )² ]

= [ 5 ( √10 + √5 ) ]/ 5

= √10 + √5

= 3.162 + 2.236

= 5.398
I hope this helps you.

: )