Question

Д)2/7*14/15+2/49*14/15-1/7*14/15+3/49*14/15; г)3/10*(3/4-5/12).​

Answer 1

Ответ:

Пошаговое объяснение:

))))))))))))))))))))))))))))))))))))))

Answer 2

Let's solve each expression step by step:

a) $\frac{2}{7} \times \frac{14}{15} + \frac{2}{49} \times \frac{14}{15} - \frac{1}{7} \times \frac{14}{15} + \frac{3}{49} \times \frac{14}{15}$

Step 1: Find a common denominator for all fractions involved. In this case, the common denominator is $7 \times 49 \times 15 = 5145$.

Step 2: Convert all fractions to have the common denominator:

$\frac{2}{7} \times \frac{14}{15} = \frac{2 \times 14 \times 49}{7 \times 15 \times 49} = \frac{2 \times 14 \times 49}{5145}$

$\frac{2}{49} \times \frac{14}{15} = \frac{2 \times 14 \times 15}{49 \times 15} = \frac{2 \times 14 \times 15}{5145}$

$\frac{1}{7} \times \frac{14}{15} = \frac{1 \times 14 \times 49}{7 \times 15 \times 49} = \frac{1 \times 14 \times 49}{5145}$

$\frac{3}{49} \times \frac{14}{15} = \frac{3 \times 14 \times 15}{49 \times 15} = \frac{3 \times 14 \times 15}{5145}$

Step 3: Combine the fractions:

$\frac{2 \times 14 \times 49}{5145} + \frac{2 \times 14 \times 15}{5145} - \frac{1 \times 14 \times 49}{5145} + \frac{3 \times 14 \times 15}{5145}$

Step 4: Perform the arithmetic:

$\frac{2 \times 14 \times 49 + 2 \times 14 \times 15 - 1 \times 14 \times 49 + 3 \times 14 \times 15}{5145}$

$\frac{98 + 42 - 49 + 63}{5145}$

$\frac{154}{5145}$

Step 5: Simplify the fraction, if possible. In this case, the fraction cannot be simplified further, so the result is:

$\frac{154}{5145}$

b) $\frac{3}{10} \times \left( \frac{3}{4} - \frac{5}{12} \right)$

Step 1: Solve the expression inside the parentheses first:

$\frac{3}{4} - \frac{5}{12}$

Step 2: Find a common denominator, which is $4 \times 12 = 48$.

Step 3: Convert both fractions to have the common denominator:

$\frac{3}{4} = \frac{3 \times 12}{4 \times 12} = \frac{36}{48}$

$\frac{5}{12} = \frac{5 \times 4}{12 \times 4} = \frac{20}{48}$

Step 4: Perform the subtraction:

$\frac{36}{48} - \frac{20}{48} = \frac{36 - 20}{48} = \frac{16}{48}$