Question

Is the number (5 + √3)(5 − √3) rational or irrational ? Justify.

Answer 1

Answer:

it is rational number

because

(a+b)(a-b)=a²-b²

(5+√3)(5-√3)

here a=5 & b=√3

so equal to (5)²–(√3)²

=25-3

=22

22 is rational number, so

(5+√3)(5-√3) also rational number