Задание 19

Question

Решите уравнения:
ewline
а) $х^2 + 3.5х - 7.5 = 0$
ewline
б) $0.3х^2 = 12 + 1.8х$

Gimli · Accepted Answer

a)
\begin{align*}
х^2 + 3.5х - 7.5 = 0\
Д = 12.25 + 7.5*4 = 12.25 + 30 = 42.25 = 6.5^2
\end{align*}
\begin{align*}
x_1 &= \frac{-3.5 + 6.5}{2} = 1.5\
x_2 &= \frac{-3.5 - 6.5}{2} = -5
\end{align*}
	extbf{Ответ: $1.5; -5$}
ewline

б) 
\begin{align*}
0.3х^2 = 12 + 1.8х\
0.3х^2 - 1.8х - 12 = 0\
Д = 1.8^2 + 14.4 = 17.64 = 4.2^2
\end{align*}
\begin{align*}
x_1 &= \frac{1.8 + 4.2}{0.6} = 10\
x_2 &= \frac{1.8 - 4.2}{0.6} = -4
\end{align*}
	extbf{Ответ: $10; -4$}

Задание 19

Answers

Comments

Задание 19

Answers

Comments

Add answer