Question

1. Tìm X

a, \(\left(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}\right)\cdot10-x=0\)

b, \(\left(\dfrac{1}{11}-\dfrac{1}{21}\right)\cdot462-2.04:\left(x+1.5\right)+11.02=30\)

c, \(\dfrac{4}{3}+x\cdot\dfrac{2}{3}-\dfrac{1}{4}=4\dfrac{5}{12}\)

Answer 1

a, (\(\dfrac{1}{2}+\dfrac{1}{6}+\dfrac{1}{12}+\dfrac{1}{20}+\dfrac{1}{30}\)).10 - x = 0

<=> \(\dfrac{5}{6}.10-x=0\)
<=> \(\dfrac{25}{3}-x=0\)
<=> x = \(\dfrac{25}{3}\) (thỏa mãn)
@Hoàng Mạnh Quân