NCERT Exemplar Solutions
Class 7 - Mathematics - Unit 8: Rational Numbers - Problems and Solutions
Question 85

Question. 85

If \(x=\dfrac{1}{10}\) and \(y=\dfrac{-3}{8}\), then evaluate \(x+y, x-y, x×y, x÷y\).

Answer:

(i) \(x+y = -\dfrac{11}{40}\)

(ii) \(x-y = \dfrac{19}{40}\)

(iii) \(x×y = -\dfrac{3}{80}\)

(iv) \(x÷y = -\dfrac{4}{15}\)

Detailed Answer with Explanation:

(i) \(\dfrac{1}{10} + \dfrac{-3}{8} = \dfrac{4-15}{40} = -\dfrac{11}{40}\).

(ii) \(\dfrac{1}{10} - \dfrac{-3}{8} = \dfrac{4+15}{40} = \dfrac{19}{40}\).

(iii) \(\dfrac{1}{10} × \dfrac{-3}{8} = -\dfrac{3}{80}\).

(iv) \(\dfrac{1}{10} ÷ \dfrac{-3}{8} = \dfrac{1}{10} × \dfrac{-8}{3} = -\dfrac{8}{30} = -\dfrac{4}{15}\).

NCERT Exemplar Solutions Class 7 – Mathematics – Unit 8: Rational Numbers – Problems and Solutions | Detailed Answers