Question

tìm x x + 2/5 = 1 - 1/6

1inhs giá trị biểu thức 3/4 - 2/5 + 5/12

giúp em ??? !!! :0  :(

Answer 1

a.x + 2/5 = 1 - 1/6

x + 2/5 = 5/6

x= 13/30

b.3/4 - 2/5 + 5/12

=7/20 + 5/12

=23/30

Answer 2

a)\(x=\left(1-\dfrac{1}{6}\right)-\dfrac{2}{5}=\dfrac{5}{6}-\dfrac{2}{5}=\dfrac{13}{30}\)

b)\(=\dfrac{7}{20}+\dfrac{5}{12}=\dfrac{23}{30}\)

Answer 3

a.x + 2/5 = 1 - 1/6

x + 2/5 = 5/6

x= 13/30

b.3/4 - 2/5 + 5/12

=7/20 + 5/12

=23/30

Answer 4

a.x + 2/5 = 1 - 1/6x + 2/5 = 5/6x= 13/30

b.3/4 - 2/5 + 5/12=7/20 + 5/12=23/30

Answer 5

\(x+\dfrac{2}{5}=1-\dfrac{1}{6}\)

\(\Leftrightarrow x+\dfrac{2}{5}=\dfrac{6-1}{6}\)

\(\Leftrightarrow x+\dfrac{2}{5}=\dfrac{5}{6}\)

\(\Leftrightarrow x=\dfrac{5}{6}-\dfrac{2}{5}\)

\(\Leftrightarrow x=\dfrac{25}{30}-\dfrac{12}{30}\)

\(\Leftrightarrow x=\dfrac{13}{30}\)

\(\dfrac{3}{4}-\dfrac{2}{5}+\dfrac{5}{12}=\dfrac{3.5.12}{240}-\dfrac{2.4.12}{240}+\dfrac{5.5.4}{240}=\dfrac{180}{240}-\dfrac{96}{240}+\dfrac{100}{240}=\dfrac{180-96+100}{240}=\dfrac{184}{240}=\dfrac{23}{30}\)