Simplify 3/8b-3/4b

$\frac{3}{8} b - \frac{3}{4} b$

Simplify each term.

Combine $\frac{3}{8}$ and $b$ .

$\frac{3 b}{8} - \frac{3}{4} b$

Combine $b$ and $\frac{3}{4}$ .

$\frac{3 b}{8} - \frac{b \cdot 3}{4}$

Move $3$ to the left of $b$ .

$\frac{3 b}{8} - \frac{3 b}{4}$

To write $- \frac{3 b}{4}$ as a fraction with a common denominator, multiply by $\frac{2}{2}$ .

$\frac{3 b}{8} - \frac{3 b}{4} \cdot \frac{2}{2}$

Write each expression with a common denominator of $8$ , by multiplying each by an appropriate factor of $1$ .

Multiply $\frac{3 b}{4}$ by $\frac{2}{2}$ .

$\frac{3 b}{8} - \frac{3 b \cdot 2}{4 \cdot 2}$

Multiply $4$ by $2$ .

$\frac{3 b}{8} - \frac{3 b \cdot 2}{8}$

Combine the numerators over the common denominator.

$\frac{3 b - 3 b \cdot 2}{8}$

Simplify the numerator.

Factor $3 b$ out of $3 b - 3 b \cdot 2$ .

Factor $3 b$ out of $3 b$ .

$\frac{3 b (1) - 3 b \cdot 2}{8}$

Factor $3 b$ out of $- 3 b \cdot 2$ .

$\frac{3 b (1) + 3 b (- 1 \cdot 2)}{8}$

Factor $3 b$ out of $3 b (1) + 3 b (- 1 \cdot 2)$ .

$\frac{3 b (1 - 1 \cdot 2)}{8}$

Multiply $- 1$ by $2$ .

$\frac{3 b (1 - 2)}{8}$

Subtract $2$ from $1$ .

$\frac{3 b \cdot - 1}{8}$

Multiply $- 1$ by $3$ .

$\frac{- 3 b}{8}$

Move the negative in front of the fraction.

$- \frac{3 b}{8}$