Question

0,2×(2х-3,5х)-4х-8=1 решити уравнение ​

Answer 1

Ответ:

х = -2 4/43

Пошаговое объяснение:

0,2*(2х - 3,5х) - 4х - 8 = 1

0,2*(-1,5х) - 4х = 1 + 8

-0,3х - 4х = 9

-4,3х = 9

х = 9/(-4,3) = -90/43

х = -2 4/43

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0,2*(2*(-90/43) - 3,5*(-90/43) - 4 * (-90/43) - 8 = 1

1/5*(-180/43 + 315/43) + 360/43 - 8 = 1

1/5*135/43 + 360/43 - 8 = 1

27/43 + 360/43 - 8 = 1

387/43 - 8 = 1

9 - 8 = 1

1 = 1 - верно

Answer 2

$0.2 \times (2x - 3.5x) - 4x - 8 = 1 \\ 0.2 \times ( - 1.5x) - 4x = 1 + 8 \\ - 0.3x - 4x = 9 \\ - 4.3x = 9 \\ x = - 9 \div 4.3 \\ x = \frac{90}{43}$