Multiplying Rational Numbers

a) [tex]\(\frac{4}{7} \times 5 = 2.857\)[/tex]

b) [tex]\(\frac{-7}{8} \times \frac{5}{8} = -0.547\)[/tex]

c) [tex]\(\frac{9}{2} \times \frac{-7}{4} = -7.875\)[/tex]

d) [tex]\(\frac{2}{3} \times \frac{-5}{9}\)[/tex]

e) [tex]\(\frac{-7}{5} \times (-2)\)[/tex]



Answer :

Sure, let's go through the process of multiplying these rational numbers step by step.

### a) [tex]\(\frac{4}{7} \times 5\)[/tex]

To multiply a fraction by a whole number, multiply the numerator of the fraction by the whole number and keep the denominator unchanged:

[tex]\[ \frac{4 \times 5}{7} = \frac{20}{7} \][/tex]

Now, convert this fraction to a decimal:

[tex]\[ \frac{20}{7} \approx 2.857 \][/tex]

### b) [tex]\(\frac{-7}{8} \times \frac{5}{8}\)[/tex]

Multiply the numerators together and the denominators together:

[tex]\[ \frac{-7 \times 5}{8 \times 8} = \frac{-35}{64} \][/tex]

Now, convert this fraction to a decimal:

[tex]\[ \frac{-35}{64} \approx -0.547 \][/tex]

### c) [tex]\(\frac{9}{2} \times \frac{-7}{4}\)[/tex]

Again, multiply the numerators together and the denominators together:

[tex]\[ \frac{9 \times -7}{2 \times 4} = \frac{-63}{8} \][/tex]

Now, convert this fraction to a decimal:

[tex]\[ \frac{-63}{8} \approx -7.875 \][/tex]

### d) [tex]\(\frac{2}{3} \times \frac{-5}{9}\)[/tex]

Multiply the numerators together and the denominators together:

[tex]\[ \frac{2 \times -5}{3 \times 9} = \frac{-10}{27} \][/tex]

Now, convert this fraction to a decimal:

[tex]\[ \frac{-10}{27} \approx -0.370 \][/tex]

### e) [tex]\(\frac{-7}{5} \times (-2)\)[/tex]

To multiply a fraction by a whole number, multiply the numerator of the fraction by the whole number and keep the denominator unchanged. Also, note that multiplying two negative numbers results in a positive number:

[tex]\[ \frac{-7 \times -2}{5} = \frac{14}{5} \][/tex]

Now, convert this fraction to a decimal:

[tex]\[ \frac{14}{5} \approx 2.8 \][/tex]

So, the detailed step-by-step results are:

a) [tex]\(\frac{4}{7} \times 5 = 2.857\)[/tex]

b) [tex]\(\frac{-7}{8} \times \frac{5}{8} = -0.547\)[/tex]

c) [tex]\(\frac{9}{2} \times \frac{-7}{4} = -7.875\)[/tex]

d) [tex]\(\frac{2}{3} \times \frac{-5}{9} = -0.370\)[/tex]

e) [tex]\(\frac{-7}{5} \times (-2) = 2.8\)[/tex]