Question

5. Dacă a=5v12-2v27-v75 atunci a este egal cu: a) 0 b) 3; c) 9; d) 81​

Answer 1

Răspuns:

$a = 5 \sqrt{12} - 2 \sqrt{27} - \sqrt{75} = 5 \times 2 \sqrt{3} - 2 \times 3 \sqrt{3} - 5 \sqrt{ 3} \\ a = 10 \sqrt{3} - 6 \sqrt{3} - 5 \sqrt{3} = - \sqrt{3}$