Question

[ 1/2 +  3/4 ] x 4

cách 1;........

cách 2;.........

Answer 1

\(\left(\dfrac{1}{2}+\dfrac{3}{4}\right)\text{×}4=\left(\dfrac{2}{4}+\dfrac{3}{4}\right)\text{×}4\\ =\dfrac{5}{4}\text{×}4=5\)

Answer 2

5

Answer 3

cách 1: \(\left[\dfrac{1}{2}+\dfrac{3}{4}\right]\times4=\left[\dfrac{2}{4}+\dfrac{3}{4}\right]\times4=\dfrac{5}{4}\times4=\dfrac{5}{4}\times\dfrac{4}{1}=\dfrac{20}{4}=5\)

cách 2 : \(\left[\dfrac{1}{2}+\dfrac{3}{4}\right]\times4=\dfrac{1}{2}+\dfrac{3}{4}\times4=\dfrac{1}{2}+\dfrac{3}{4}\times\dfrac{4}{1}=\dfrac{1}{2}+\dfrac{12}{4}=\dfrac{1}{2}+\dfrac{3}{4}=\dfrac{2}{4}+\dfrac{3}{4}=\dfrac{5}{4}\)