

InterviewSolution
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Verify commutativity of addition of rational numbers for each of the following pairson of rational numbers:(i) \(\frac{-11}{5}\) and \(\frac{4}{7}\)(ii) \(\frac{4}{9}\) and \(\frac{7}{-12}\)(iii) \(\frac{-3}{5}\) and \(\frac{-2}{-15}\)(iv) \(\frac{2}{-7}\) and \(\frac{12}{-35}\)(v) 4 and \(\frac{-3}{5}\)(vi) -4 and \(\frac{4}{-7}\) |
Answer» (i) The addition of rational number is commutative i.e, if \(\frac{a}{b}\) and \(\frac{c}{d}\) are any two rational numbers, then \(\frac{a}{b}+\frac{c}{d}=\frac{c}{d}+\frac{a}{b}\) Verification: In order to verify this property, Let us consider two expressions: \(\frac{-11}{5}+\frac{4}{7}\) And, \(\frac{4}{7}+\frac{-11}{5}\) We have: \(\frac{-11}{5}+\frac{4}{7}=\frac{-77}{35}+\frac{20}{35}\) = \(\frac{-77+20}{35}\) = \(\frac{-57}{35}\) And, \(\frac{4}{7}+\frac{-11}{5}=\frac{20}{35}+\frac{-77}{35}\) = \(\frac{20-77}{35}\) = \(\frac{-57}{35}\) Therefore, \(\frac{-11}{5}+\frac{4}{7}=\frac{4}{7}+\frac{-11}{5}\) (ii) The addition of rational number is commutative i.e, if \(\frac{a}{b}\) and \(\frac{c}{d}\) are any two rational numbers, then \(\frac{a}{b}+\frac{c}{d}=\frac{c}{d}+\frac{a}{b}\) Verification: In order to verify this property, Let us consider two expressions: \(\frac{4}{9}+\frac{-7}{12}\) And, \(\frac{-7}{12}+\frac{4}{9}\) We have: \(\frac{4}{9}+\frac{-7}{12}=\frac{16}{36}+\frac{-21}{36}\) = \(\frac{16-21}{36}\) = \(\frac{-5}{36}\) And, \(\frac{-7}{12}+\frac{4}{9}=\frac{-21}{36}+\frac{16}{36}\) \(=\frac{-21+16}{36}\) = \(\frac{-5}{36}\) Therefore, \(\frac{4}{9}+\frac{-7}{12}=\frac{-7}{12}+\frac{4}{9}\) (iii) The addition of rational number is commutative i.e, if \(\frac{a}{b}\) and \(\frac{c}{d}\)are any two rational numbers, then \(\frac{a}{b}+\frac{c}{d}=\frac{c}{d}+\frac{a}{b}\) Verification: In order to verify this property, Let us consider two expressions: \(\frac{3}{5}+\frac{-2}{-15}\) And, \(\frac{-2}{-15}+\frac{3}{5}\) We have: \(\frac{3}{5}+\frac{-2}{-15}=\frac{-3}{5}+\frac{2}{15}\) = \(\frac{-9+2}{15}\) = \(\frac{-7}{15}\) And, \(\frac{-2}{-15}+\frac{3}{5}=\frac{-2}{-15}+\frac{3}{5}\) = \(\frac{2-9}{15}\) = \(\frac{-7}{15}\) Therefore, \(\frac{3}{5}+\frac{-2}{-15}=\frac{-2}{-15}+\frac{3}{5}\) (iv) The addition of rational number is commutative i.e, if \(\frac{a}{b}\) and \(\frac{c}{d}\) are any two rational numbers, then \(\frac{a}{b}+\frac{c}{d}=\frac{c}{d}+\frac{a}{b}\) Verification: In order to verify this property, Let us consider two expressions: \(\frac{2}{-7}+\frac{12}{-35}\) And, \(\frac{12}{-35}+\frac{2}{-7}\) We have: \(\frac{2}{-7}+\frac{12}{-35}=\frac{-10}{35}+\frac{-12}{35}\) = \(\frac{-10-12}{35}\) = \(\frac{-22}{35}\) And, \(\frac{12}{-35}+\frac{2}{7}=\frac{-12}{35}+\frac{-10}{35}\) = \(\frac{-12-10}{35}\) = \(\frac{-22}{35}\) Therefore, \(\frac{2}{-7}+\frac{12}{-35}=\frac{12}{-35}+\frac{2}{-7}\) (v) The addition of rational number is commutative i.e, if \(\frac{a}{b}\) and \(\frac{c}{d}\) are any two rational numbers, then \(\frac{a}{b}+\frac{c}{d}=\frac{c}{d}+\frac{a}{b}\) Verification: In order to verify this property, Let us consider two expressions: \(4+\frac{-3}{5}\) And, \(\frac{-3}{5}+4\) We have: \(4+\frac{-3}{5}\)=\(\frac{20}{5}-\frac{3}{5}\) = \(\frac{20-3}{5}\) = \(\frac{17}{5}\) And, \(\frac{-3}{5}+4\)= \(\frac{-3}{5}+\frac{20}{5}\) = \(\frac{-3+20}{5}\) = \(\frac{17}{5}\) Therefore, \(4+\frac{-3}{5}\)= \(\frac{-3}{5}+4\) (vi) The addition of rational number is commutative i.e, if \(\frac{a}{b}\) and \(\frac{c}{d}\) are any two rational numbers, then \(\frac{a}{b}+\frac{c}{d}=\frac{c}{d}+\frac{a}{b}\) Verification: In order to verify this property, Let us consider two expressions: \(-4+\frac{4}{-7}\) And, \(\frac{4}{-7}-4\) We have: \(-4+\frac{4}{-7}\)=\(\frac{-28}{7}-\frac{4}{7}\) = \(\frac{-28-4}{7}\) = \(\frac{-32}{7}\) And, \(\frac{4}{-7}-4\)=\(\frac{-4}{7}-\frac{28}{7}\) = \(\frac{-4-28}{7}\) = \(\frac{-32}{7}\) Therefore, \(-4+\frac{4}{-7}\)=\(\frac{4}{-7}-4\) |
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