Pre-Algebra Examples

$- \frac{3}{4} + \frac{7}{8} - \frac{1}{10}$

Step 1

Find the common denominator.

Tap for more steps...

Step 1.1

Multiply $\frac{3}{4}$ by $\frac{10}{10}$ .

$- (\frac{3}{4} \cdot \frac{10}{10}) + \frac{7}{8} - \frac{1}{10}$

Step 1.2

Multiply $\frac{3}{4}$ by $\frac{10}{10}$ .

$- \frac{3 \cdot 10}{4 \cdot 10} + \frac{7}{8} - \frac{1}{10}$

Step 1.3

Multiply $\frac{7}{8}$ by $\frac{5}{5}$ .

$- \frac{3 \cdot 10}{4 \cdot 10} + \frac{7}{8} \cdot \frac{5}{5} - \frac{1}{10}$

Step 1.4

Multiply $\frac{7}{8}$ by $\frac{5}{5}$ .

$- \frac{3 \cdot 10}{4 \cdot 10} + \frac{7 \cdot 5}{8 \cdot 5} - \frac{1}{10}$

Step 1.5

Multiply $\frac{1}{10}$ by $\frac{4}{4}$ .

$- \frac{3 \cdot 10}{4 \cdot 10} + \frac{7 \cdot 5}{8 \cdot 5} - (\frac{1}{10} \cdot \frac{4}{4})$

Step 1.6

Multiply $\frac{1}{10}$ by $\frac{4}{4}$ .

$- \frac{3 \cdot 10}{4 \cdot 10} + \frac{7 \cdot 5}{8 \cdot 5} - \frac{4}{10 \cdot 4}$

Step 1.7

Multiply $4$ by $10$ .

$- \frac{3 \cdot 10}{40} + \frac{7 \cdot 5}{8 \cdot 5} - \frac{4}{10 \cdot 4}$

Step 1.8

Reorder the factors of $8 \cdot 5$ .

$- \frac{3 \cdot 10}{40} + \frac{7 \cdot 5}{5 \cdot 8} - \frac{4}{10 \cdot 4}$

Step 1.9

Multiply $5$ by $8$ .

$- \frac{3 \cdot 10}{40} + \frac{7 \cdot 5}{40} - \frac{4}{10 \cdot 4}$

Step 1.10

Reorder the factors of $10 \cdot 4$ .

$- \frac{3 \cdot 10}{40} + \frac{7 \cdot 5}{40} - \frac{4}{4 \cdot 10}$

Step 1.11

Multiply $4$ by $10$ .

$- \frac{3 \cdot 10}{40} + \frac{7 \cdot 5}{40} - \frac{4}{40}$

Step 2

Combine the numerators over the common denominator.

$\frac{- 3 \cdot 10 + 7 \cdot 5 - 4}{40}$

Step 3

Simplify each term.

Tap for more steps...

Step 3.1

Multiply $- 3$ by $10$ .

$\frac{- 30 + 7 \cdot 5 - 4}{40}$

Step 3.2

Multiply $7$ by $5$ .

$\frac{- 30 + 35 - 4}{40}$

Step 4

Simplify by adding and subtracting.

Tap for more steps...

Step 4.1

Add $- 30$ and $35$ .

$\frac{5 - 4}{40}$

Step 4.2

Subtract $4$ from $5$ .

$\frac{1}{40}$

Step 5

The result can be shown in multiple forms.

Exact Form:

$\frac{1}{40}$

Decimal Form:

$0.025$