question_answer

(a) \[\frac{-9}{10}+\frac{22}{15}\]

(b) \[\frac{5}{63}-\left( \frac{-6}{21} \right)\]

(c) \[\frac{-6}{5}\times \frac{9}{11}\]

Answer:

(a) \[\frac{-9}{10}+\frac{22}{15}=\frac{-9\times 3+22\times 2}{30}\]

\[=\frac{-27+44}{30}=\frac{17}{30}\]

(b) \[\frac{5}{63}+\left( \frac{-6}{21} \right)=\frac{5}{63}+\frac{6}{21}=\frac{5+6\times 3}{63}\]

\[=\frac{5+18}{63}=\frac{23}{63}\]

(c) \[\frac{-6}{5}+\frac{9}{11}=-\left( \frac{6}{5}\times \frac{9}{11} \right)=-\left( \frac{54}{55} \right)\]

\[=\frac{-54}{55}\]