Question

1/4+3/7= 1/2-3/8= 3/5+(1/2-0,1)= 4/5-2/15=

Answer 1

1/4+3/7=0,678571429

1/2-3/8=0,125

4/5-2/15=0,666666667

Answer 2

7/28+12/28 = 19/28

4/8-3/8 = 1/8

0.6+0.4=1

12/15-2/15=10/15=1/3

Answer 3

Let's solve these step by step:

1. $\frac{1}{4} + \frac{3}{7}$

To add these fractions, we need a common denominator, which is the least common multiple (LCM) of 4 and 7, which is 28.

$\frac{1}{4}$ needs to be multiplied by $\frac{7}{7}$ to have a denominator of 28, and $\frac{3}{7}$ needs to be multiplied by $\frac{4}{4}$ to have a denominator of 28.

So, $\frac{1}{4} + \frac{3}{7} = \frac{7}{28} + \frac{12}{28} = \frac{19}{28}$.

2. $\frac{1}{2} - \frac{3}{8}$

Subtracting fractions also requires a common denominator. The LCM of 2 and 8 is 8.

$\frac{1}{2}$ needs to be multiplied by $\frac{4}{4}$ to have a denominator of 8, and $\frac{3}{8}$ already has the correct denominator.

So, $\frac{1}{2} - \frac{3}{8} = \frac{4}{8} - \frac{3}{8} = \frac{1}{8}$.

3. $\frac{3}{5} + \left( \frac{1}{2} - 0.1 \right)$

Let's simplify the inner part first:

$\frac{1}{2} - 0.1 = \frac{1}{2} - \frac{1}{10} = \frac{5}{10} - \frac{1}{10} = \frac{4}{10} = \frac{2}{5}$.

Now the whole expression becomes:

$\frac{3}{5} + \frac{2}{5} = \frac{3+2}{5} = \frac{5}{5} = 1$.

4. $\frac{4}{5} - \frac{2}{15}$

The common denominator here is 15.

$\frac{4}{5}$ needs to be multiplied by $\frac{3}{3}$ to have a denominator of 15, and $\frac{2}{15}$ already has the correct denominator.

So, $\frac{4}{5} - \frac{2}{15} = \frac{12}{15} - \frac{2}{15} = \frac{10}{15} = \frac{2}{3}$.

To summarize:

1. $\frac{1}{4} + \frac{3}{7} = \frac{19}{28}$
2. $\frac{1}{2} - \frac{3}{8} = \frac{1}{8}$ 0 0