Question

Tính:

\(a.\dfrac{1}{5}+\dfrac{-3}{4}\)            \(b.\dfrac{1}{3}-\dfrac{1}{6}\)

Answer 1

\(\dfrac{1}{5}+\dfrac{-3}{4}=\dfrac{4}{20}+\dfrac{-15}{20}=\dfrac{-11}{20}\)

\(\dfrac{1}{3}-\dfrac{1}{6}=\dfrac{2}{6}-\dfrac{1}{6}=\dfrac{1}{6}\)

Answer 2

Tính:

a. 1/5 + -3/4

= \(\dfrac{\text{1 x 4}}{\text{5 x 4}}+\dfrac{\text{-3 x 5 }}{\text{4 x 5}}=\dfrac{4}{20}+\dfrac{-15}{20}=\dfrac{4+\left(-15\right)}{20}=\dfrac{-11}{20}\)

b. 1/3 - 1/6

= \(\dfrac{\text{1 x 2}}{\text{3 x 2}}-\dfrac{1}{6}=\dfrac{\text{2}}{6}-\dfrac{1}{6}=\dfrac{1}{6}.\)