Question

$9a - \sqrt{72ab} + \sqrt{18ab}$
помогите

Answer 1

$9a-\sqrt{72ab}+\sqrt{18ab} =9a-\sqrt{36*2ab}+\sqrt{9*2ab}=9a-6\sqrt{2ab}+3\sqrt{2ab} =9a-3\sqrt{2ab}=(3\sqrt{a})^{2}-3\sqrt{2ab}=3\sqrt{a}(3\sqrt{a}-\sqrt{2b})$

Answer 2

9a-√72ab + √18ab = 9a-√(36×2ab)+√(9×2ab)=9a-6√(2ab)+3√(2ab)=

=9a-3√(2ab)

(ab≥0)