Question

Найдите все корни уравнения:
(-3t-1)^2=16
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Answer 1

Объяснение:

${( - 3t - 1)}^{2} = 16 \\ 9 {t}^{2} + 6t + 1 - 16 = 0 \\ 9 {t}^{2} + 6t - 15 = 0 \\ d = {b}^{2} - 4ac = 36 - 4 \times 9 \times ( - 15) = \sqrt{576} = 24 \\ t1 = \frac{ - 6 + 24}{2 \times 9} = \frac{18}{18} = 1 \\ t2 = \frac{ - 6 - 24}{18} = \frac{ - 30}{18} = - \frac{5}{3}$