Question

(7+3√2) ×(7-3√2)= ?​

Answer 1

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

${7}^{2} - {(3 \sqrt{2}) }^{2} \\ 49 - 9 \times 2 \\ 49 - 18 \\ 31$

Answer 2

heyy!!

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

(a+b)×(a-b)=(a)^2-(b)^2

${7}^{2} - {3 \sqrt{2} }^{2}$

$49 - 18$

$31$