Question

how to solve irrational numbers​

Answer 1

Multiplication of terms involving irrational numbers is just as normal multiplication of binomial.

Suppose, ( a + b) ( c + d)

This is written as a ( c + d) + b (c + d)

Follow the same method in here.

Given,

$(5 + \sqrt{7} )(2 + \sqrt{5} ) \\ \\ = 5(2 + \sqrt{5} ) + \sqrt{7} (2 + \sqrt{5} ) \\ \\ = 5(2) + 5( \sqrt{5} ) + \sqrt{7} (2) + \sqrt{7} ( \sqrt{5} ) \\ \\ = 10 + 5 \sqrt{5} + 2 \sqrt{7} + \sqrt{35}$

Therefore, (5 + √7)(2+√5) = 10 + 5√5+2√7+√35