Question

реши уравнение (1-7/9)х=8
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Answer 1

Ответ:

$x = 36$

Пошаговое объяснение:

I способ.

$\bigg( 1 - \dfrac{7}{9} \bigg) \cdot x = 8$

$\bigg( \dfrac{9}{9} - \dfrac{7}{9} \bigg)\cdot x=8$

$\bigg(\dfrac{9-7}{9}\bigg) \cdot x = 8$

$\dfrac{2}{9} \cdot x = 8$

$\dfrac{2}{9} x= 8$

$x = 8 : \dfrac{2}{9}$

$x = \dfrac{8}{1} \cdot \dfrac{9}{2}$

$x = \dfrac{8: 2}{1} \cdot \dfrac{9}{2 : 2}$

$x = 4 \cdot 9$

$x=36$

II способ.

$\bigg( 1 - \dfrac{7}{9} \bigg) \cdot x = 8$

$1 \cdot x - \dfrac{7}{9} \cdot x = 8$

$x - \dfrac{7}{9} x= 8$

$\dfrac{9}{9}x - \dfrac{7}{9} x= 8$

$\dfrac{9x-7x}{9} = 8$

$\dfrac{2x}{9} =8$

$\dfrac{2}{9} x=8$

$x = 8 : \dfrac{2}{9}$

$x = \dfrac{8}{1} \cdot \dfrac{9}{2}$

$x = \dfrac{8: 2}{1} \cdot \dfrac{9}{2 : 2}$

$x = 4 \cdot 9$

$x= 36$

Проверка:

$\bigg( 1 - \dfrac{7}{9} \bigg) \cdot36= 8$

$\bigg( \dfrac{9}{9} - \dfrac{7}{9} \bigg)\cdot 36=8$

$\bigg(\dfrac{9-7}{9}\bigg) \cdot 36 = 8$

$\dfrac{2}{9} \cdot \dfrac{36}{1} =8$

$\dfrac{2}{9:9} \cdot \dfrac{36 : 9}{1} =8$

$2 \cdot 4 = 8$

$8 = 8$ - верно