Question

1,1x^2-4,4x-5,5=0 решите пример

Answer 1

$1.1 {x}^{2} - 4.4x - 5.5 = 0 \: | \div 1.1| \\ {x}^{2} - 4x - 5 = 0 \\ d =16 - 4 \times ( - 5) = 16 + 20 = 36 \\ x1 = \frac{4 + \sqrt{36} }{2} = \frac{4 + 6}{2} = 5 \\ x2 = \frac{4 - 6}{2} = - 1$

Проверка:

x=5

$1.1 \times {5}^{2} - 4.4 \times 5 - 5.5 = 0 \\ 27.5 - 22 - 5.5 = 0 \\ 0 = 0$

верно.

x=-1

$1.1 \times {( - 1)}^{2} - 4.4 \times ( - 1) - 5.5 = 0 \\ 1.1 + 4.5 - 5.5 = 0 \\ 0 = 0$

верно.

$x1 = 5. \: \: x2 = - 1.$