Question

12√18-6√20-3√50+8√45-21√2+12√5

Answer 1

GIVEN
12√18 - 6√20 - 3√50 + 8√45 - 21√2 + 12√5
$= \: 12 \sqrt{2 \times 9} - 6 \sqrt{4 x 5} - 3 \sqrt{25 \times 2} \\ + 8 \sqrt{9 \times 5} - 21 \sqrt{2} + 12 \sqrt{5} \\ = \: 12 \times 3 \sqrt{2} - 6 \times 2 \sqrt{5} + 3 \times 5 \sqrt{2} \\ + 8 \times 3 \sqrt{5} - 21 \sqrt{2} + 12 \sqrt{5} \\ = 36 \sqrt{2} - 12 \sqrt{5} + 15 \sqrt{2} + 24 \sqrt{5} - 21 \sqrt{2} + 12 \sqrt{5} \\ = (36 \sqrt{2} + 15 \sqrt{2} - 21 \sqrt{2} ) + ( - 12 \sqrt{5} + 24 \sqrt{5} + 12 \sqrt{5}) \\ = 30 \sqrt{2} + 24 \sqrt{5} \\ therefore \: this \: the \: solution$