Question

-0,4x-1,8=2+0,5x -2(x+8)+9=-3(x-8) 16/21x - 2,48=3/7x-1,18

Answer 1

1)-0,4x-1,8=2+0,5x

-0.4x-0,5x=2+1.8

-0.9x=3.8

x=-38/9

2)-2(x+8)+9=-3(x-8)

-2x-16+9=-3x+24

-2x-7=-3x+24

-2x+3x=24+7

x=31

3)16/21x - 2,48=3/7x-1,18

16/21x-62/25=3/7x-59/50

800x-2604=450x-1239

800x-450x=-1239+2604

350x=1365

x=39/10

Answer 2

To solve the equations, let's go step by step:

1. -0.4x - 1.8 = 2 + 0.5x

First, let's combine like terms by adding 0.4x to both sides and adding 1.8 to both sides:

-0.4x + 0.4x - 1.8 + 1.8 = 2 + 0.5x + 0.4x

This simplifies to:

0 = 2 + 0.9x

Next, let's isolate x by subtracting 2 from both sides:

0 - 2 = 2 + 0.9x - 2

-2 = 0.9x

Finally, divide both sides by 0.9 to solve for x:

x = -2 / 0.9 x = -2.22 (rounded to two decimal places)

2. -2(x + 8) + 9 = -3(x - 8)

First, distribute the -2 and -3:

-2x - 16 + 9 = -3x + 24

Combine like terms:

-2x - 7 = -3x + 24

Now, let's isolate x by adding 3x to both sides:

-2x + 3x - 7 = -3x + 3x + 24

x - 7 = 24

Finally, add 7 to both sides to find the value of x:

x - 7 + 7 = 24 + 7

x = 31

3. 16/21x - 2.48 = 3/7x - 1.18

To eliminate the fractions, let's multiply both sides by the least common multiple (LCM) of the denominators, which is 21 for this case:

21 * (16/21x) - 21 * 2.48 = 21 * (3/7x) - 21 * 1.18

The fractions cancel out:

16x - 52.08 = 9x - 24.78

Now, let's isolate x by subtracting 9x from both sides:

16x - 9x - 52.08 = 9x - 9x - 24.78

7x - 52.08 = -24.78

Next, add 52.08 to both sides:

7x - 52.08 + 52.08 = -24.78 + 52.08

7x = 27.30

Finally, divide both sides by 7 to solve for x:

x = 27.30 / 7 x ≈ 3.90 (rounded to two decimal places)

So, the solutions to the equations are:

1. x ≈ -2.22
2. x = 31
3. x ≈ 3.90