Question

3)2 2/3х-1 5/7=3 1/21

Answer 1

Ответ:

$1\dfrac{11}{14}$

Пошаговое объяснение:

$2\dfrac{2}{3}x-1\dfrac{5}{7}=3\dfrac{1}{21} \quad \bigg | \quad \cdot 21$

$\dfrac{2 \cdot 3+2}{3}x \cdot 21-\dfrac{1 \cdot 7+5}{7} \cdot 21=\dfrac{3 \cdot 21+1}{21} \cdot 21;$

$\dfrac{8}{3}x \cdot 21-\dfrac{12}{7} \cdot 21=\dfrac{64}{21} \cdot 21;$

$8x \cdot 7-12 \cdot 3=64;$

$56x-36=64;$

$56x=36+64;$

$56x=100;$

$x=\dfrac{100}{56};$

$x=\dfrac{25}{14};$

$x=1\dfrac{11}{14};$