Find the best solutions to your problems with the help of IDNLearn.com's expert users. Join our interactive community and get comprehensive, reliable answers to all your questions.

10. The value of [tex]\frac{3}{5}+\left(-\frac{1}{2}\right)-\frac{2}{3} \div \frac{8}{9}[/tex] is:

(a) [tex]\frac{12}{20}[/tex]
(b) [tex]-\frac{13}{20}[/tex]
(c) [tex]-\frac{15}{27}[/tex]
(d) [tex]-\frac{12}{27}[/tex]


Sagot :

To find the value of [tex]\(\frac{3}{5}+\left(-\frac{1}{2}\right)-\frac{2}{3} \div \frac{8}{9}\)[/tex], we will follow these steps:

1. Simplify the division:
We need to divide [tex]\(\frac{2}{3}\)[/tex] by [tex]\(\frac{8}{9}\)[/tex]. Dividing by a fraction is the same as multiplying by its reciprocal. Thus:
[tex]\[ \frac{2}{3} \div \frac{8}{9} = \frac{2}{3} \times \frac{9}{8} \][/tex]
To multiply two fractions, we multiply the numerators and the denominators:
[tex]\[ \frac{2 \times 9}{3 \times 8} = \frac{18}{24} \][/tex]
Simplify [tex]\(\frac{18}{24}\)[/tex] by dividing both the numerator and the denominator by their greatest common divisor, which is 6:
[tex]\[ \frac{18 \div 6}{24 \div 6} = \frac{3}{4} \][/tex]

2. Perform the remaining operations:
We now substitute [tex]\(\frac{3}{4}\)[/tex] for [tex]\(\frac{2}{3} \div \frac{8}{9}\)[/tex] in the original expression:
[tex]\[ \frac{3}{5} + \left(-\frac{1}{2}\right) - \frac{3}{4} \][/tex]

3. Find a common denominator:
To add and subtract these fractions, they need a common denominator. The denominators are 5, 2, and 4. The least common multiple (LCM) of these numbers is 20. Convert each fraction:
[tex]\[ \frac{3}{5} = \frac{3 \times 4}{5 \times 4} = \frac{12}{20} \][/tex]
[tex]\[ -\frac{1}{2} = -\frac{1 \times 10}{2 \times 10} = -\frac{10}{20} \][/tex]
[tex]\[ \frac{3}{4} = \frac{3 \times 5}{4 \times 5} = \frac{15}{20} \][/tex]

4. Combine the fractions:
Now that we have a common denominator, we can combine:
[tex]\[ \frac{12}{20} + \left(-\frac{10}{20}\right) - \frac{15}{20} \][/tex]
[tex]\[ = \frac{12 - 10 - 15}{20} \][/tex]
[tex]\[ = \frac{12 - 10 - 15}{20} \][/tex]
[tex]\[ = \frac{-13}{20} \][/tex]

Therefore, the value of [tex]\(\frac{3}{5}+\left(-\frac{1}{2}\right)-\frac{2}{3} \div \frac{8}{9}\)[/tex] is

[tex]\[ \boxed{-\frac{13}{20}} \][/tex]