Solve for u 15=-15-8u

$15 = - 15 - 8 u$

Step 1

Rewrite the equation as $- 15 - 8 u = 15$ .

$- 15 - 8 u = 15$

Step 2

Move all terms not containing $u$ to the right side of the equation.

Add $15$ to both sides of the equation.

$- 8 u = 15 + 15$

Add $15$ and $15$ .

$- 8 u = 30$

Step 3

Divide each term in $- 8 u = 30$ by $- 8$ and simplify.

Divide each term in $- 8 u = 30$ by $- 8$ .

$\frac{- 8 u}{- 8} = \frac{30}{- 8}$

Simplify the left side.

Cancel the common factor of $- 8$ .

Cancel the common factor.

$\frac{- 8 u}{- 8} = \frac{30}{- 8}$

Divide $u$ by $1$ .

$u = \frac{30}{- 8}$

Simplify the right side.

Cancel the common factor of $30$ and $- 8$ .

Factor $2$ out of $30$ .

$u = \frac{2 (15)}{- 8}$

Cancel the common factors.

Factor $2$ out of $- 8$ .

$u = \frac{2 \cdot 15}{2 \cdot - 4}$

Cancel the common factor.

$u = \frac{2 \cdot 15}{2 \cdot - 4}$

Rewrite the expression.

$u = \frac{15}{- 4}$

Move the negative in front of the fraction.

$u = - \frac{15}{4}$

Step 4

The result can be shown in multiple forms.

Exact Form:

$u = - \frac{15}{4}$

Decimal Form:

$u = - 3.75$

Mixed Number Form:

$u = - 3 \frac{3}{4}$