Question

Thực hiện phép tính:

a) 11\(\dfrac{3}{4}\)-(6\(\dfrac{5}{6}\)-4\(\dfrac{1}{2}\)+1\(\dfrac{2}{3}\))     b) (17\(\dfrac{13}{15}\)-3\(\dfrac{3}{7}\))-(2\(\dfrac{12}{15}\)-4)

Answer 1

a: \(11\dfrac{3}{4}-\left(6\dfrac{5}{6}-4\dfrac{1}{2}+1\dfrac{2}{3}\right)\)

\(=11+\dfrac{3}{4}-6-\dfrac{5}{6}+4+\dfrac{1}{2}-1-\dfrac{2}{3}\)

\(=10+\dfrac{3}{4}-\dfrac{5}{6}+\dfrac{1}{2}-\dfrac{2}{3}\)

\(=10+\dfrac{9}{12}-\dfrac{10}{12}+\dfrac{6}{12}-\dfrac{8}{12}\)

\(=10-\dfrac{3}{12}=10-\dfrac{1}{4}=\dfrac{39}{4}\)

b: \(\left(17\dfrac{13}{15}-3\dfrac{3}{7}\right)-\left(2\dfrac{12}{15}-4\right)\)

\(=17+\dfrac{13}{15}-3-\dfrac{3}{7}-2-\dfrac{12}{15}+4\)

\(=16+\dfrac{13}{15}-\dfrac{3}{7}-\dfrac{12}{15}\)

\(=16+\dfrac{1}{15}-\dfrac{3}{7}=\dfrac{1642}{105}\)