Question

The value of ( sqrt 5 + sqrt 2 )( sqrt 5 - sqrt 2 )is: (a) 10 (b) 7 (c) 3 (d) sqrt(3

Answer 1

(c) 3

Explanation:

`(√(5) +√(2) )(√(5) -√(2) )=(√(5) )^(2) -(√(2) )^(2) =5-2=3`

Hope this helps

Answer 2

C) 3

Explanation:

This is just a differences of squares:

`(a+b)(a-b)=(a^2-b^2)\\\\(√(5)+√(2))(√(5)-√(2))=(√(5)^2-√(2)^2)=5-2=3`