Question

2 задания __________​

Answer 1

$\frac{a^{2}-12a+36 }{36-a^{2} } = \frac{(a-6)^{2} }{(6-a)(6+a)}= -\frac{a-6}{6+a}$

7² = 5² + 8² - 2 · 5 · 8 · cos α

cos α = (5² + 8² - 7²) ÷ 80 = (25 + 64 - 49) ÷ 80 = 40 ÷ 80 = 0,5 ⇒ α = 60°