Question

ребята помогите пожалуйста сделать 3 целых 11/15-(2 целых9/20+1целая7/30

Answer 1

$3\frac{11}{15}-(2 \frac{9}{20}+1 \frac{7}{30})=\frac{1}{20}\\\\ 1)2\frac{9}{20}+1 \frac{7}{30}= \frac{49}{20}+ \frac{37}{30}= \frac{49*3}{60}+ \frac{37*2}{60}=\frac{147+74}{60}= \frac{221}{60}\\\\2)3\frac{11}{15}- \frac{221}{60}= \frac{56}{15}- \frac{221}{60}=\frac{56*4}{60}-\frac{221}{60}= \frac{224-221}{60}= \frac{3}{60}= \frac{1}{20}$