Question

How would you do this problem?

Answer 1

Use conjugate pair theorem on the denominator.

4/(5+5sqrt(2)) x (5-5sqrt(2))/(5-5sqrt(2))

The numerator would become 20-20sqrt(2)

Denominator would become (25 x 25 x 2) = 1250

The answer would be (20(1-sqrt2))/1250 <-- simplify if you want

Answer 2

first you would do the square root of two which is about 1.4. now you would do 10+1.4 which is 11.4. now you do 4 divided by 11.4 which is about 0.4