Question

срочно!

$\sqrt{7} \times \sqrt{63} = {?}$

$\sqrt{8} \times \sqrt{98} =$

$\sqrt{75} \times \sqrt{3} =$

Answer 1

$\sqrt{7} \times \sqrt{63} = \sqrt{7 \times 7 \times 9} = 7 \times 3 = 21 \\ \sqrt{8} \times \sqrt{98} = \sqrt{8 \times 2 \times 49} = \sqrt{16 \times 49} = 4 \times 7 = 28 \\ \sqrt{75} \times \sqrt{3} = \sqrt{25 \times 3 \times 3} = 5 \times 3 = 15$