Question

Simplify
$(2 + 3 \sqrt{7)} (2 - 3 \sqrt{7)}$

Answer 1

Hey!!

We will use the identity here

a² - b² = (a + b)(a - b)

Thus (2 + 3√7)(2 - 3√7)

=> 2² - (3√7)²

=> 4 - 63

=> -59

Hope this helps

Answer 2

$(2 + 3 \sqrt{7} )(2 - 3 \sqrt{7} ) \\ \\ = {(2)}^{2} - {(3 \sqrt{7}) }^{2} \\ \\ {a}^{2} - {b}^{2} = (a + b)(a - b) \\ \\ = 4 - 63 \\ \\ = - 59$