What is the value of x in the equation StartFraction 4 Over 7 EndFraction (StartFraction 21 Over 8 EndFraction x + one-half) = negative 2 (StartFraction 1 Over 7 EndFraction minus StartFraction 5 Over 28 EndFraction x)? Write your solution in decimal form.

1 answer

To solve the equation

\[ \frac{4}{7}\left(\frac{21}{8}x + \frac{1}{2}\right) = -2\left(\frac{1}{7} - \frac{5}{28}x\right), \]

we start by simplifying both sides.

Step 1: Simplifying the left side

Distributing \(\frac{4}{7}\):

\[ \frac{4}{7} \cdot \frac{21}{8}x + \frac{4}{7} \cdot \frac{1}{2}. \]

Calculating \(\frac{4}{7} \cdot \frac{21}{8}x\):

\[ \frac{4 \cdot 21}{7 \cdot 8}x = \frac{84}{56}x = \frac{3}{2}x. \]

Next, calculating \(\frac{4}{7} \cdot \frac{1}{2}\):

\[ \frac{4 \cdot 1}{7 \cdot 2} = \frac{4}{14} = \frac{2}{7}. \]

So the left side simplifies to:

\[ \frac{3}{2}x + \frac{2}{7}. \]

Step 2: Simplifying the right side

Distributing \(-2\):

\[ -2 \cdot \frac{1}{7} + (-2) \cdot \left(- \frac{5}{28}x\right). \]

Calculating \(-2 \cdot \frac{1}{7}\):

\[ -\frac{2}{7}. \]

Calculating \(-2 \cdot \left(-\frac{5}{28}x\right)\):

\[ \frac{10}{28}x = \frac{5}{14}x. \]

So the right side simplifies to:

\[ -\frac{2}{7} + \frac{5}{14}x. \]

Step 3: Setting the simplified forms equal

Now we have

\[ \frac{3}{2}x + \frac{2}{7} = -\frac{2}{7} + \frac{5}{14}x. \]

Step 4: Combining like terms

To eliminate the fractions, we can multiply through by the least common multiple of the denominators, which is 14:

\[ 14\left(\frac{3}{2}x + \frac{2}{7}\right) = 14\left(-\frac{2}{7} + \frac{5}{14}x\right). \]

Calculating each side:

\[ 14 \cdot \frac{3}{2}x + 14 \cdot \frac{2}{7} = 21x + 4, \] \[ 14 \cdot -\frac{2}{7} + 14 \cdot \frac{5}{14}x = -4 + 5x. \]

So we have:

\[ 21x + 4 = -4 + 5x. \]

Step 5: Moving terms involving \(x\) to one side

Rearranging gives:

\[ 21x - 5x = -4 - 4. \]

This simplifies to:

\[ 16x = -8. \]

Step 6: Solving for \(x\)

Dividing both sides by 16:

\[ x = -\frac{8}{16} = -\frac{1}{2}. \]

Decimal Form:

Thus, in decimal form, the solution is:

\[ x = -0.5. \]

So the final answer is:

\[ \boxed{-0.5}. \]