B1: x = ? : Quy tắc chuyển vế
a, x + \(\dfrac{1}{2}=-\dfrac{6}{7}\) b, x - \(\dfrac{3}{4}=\dfrac{9}{8}\)
c, x + 7,25 = 15,75 d, \(\left(-\dfrac{1}{3}\right)-x=\dfrac{17}{6}\)
e, x - \(\left(\dfrac{5}{4}-\dfrac{7}{5}\right)=\dfrac{9}{20}\) g, 9 - x = \(\dfrac{8}{7}-\left(-\dfrac{7}{8}\right)\)
B2: Tính:
a, \(\dfrac{17}{11}.\left(\dfrac{6}{5}-\dfrac{16}{11}\right)+\dfrac{26}{5}\)
b, \(\dfrac{39}{5}+\left(\dfrac{9}{4}-\dfrac{9}{5}\right)-\left(\dfrac{5}{4}+\dfrac{6}{7}\right)\)
Bài 1:
a: x=-6/7-1/2=-12/14-7/14=-19/14
b: \(x=\dfrac{9}{8}+\dfrac{3}{4}=\dfrac{9}{8}+\dfrac{6}{8}=\dfrac{15}{8}\)
c: \(x=15.75-7.25=8.5\)
d: \(x=\dfrac{-1}{3}-\dfrac{17}{6}=-\dfrac{19}{6}\)
e: \(x=\dfrac{9}{20}+\dfrac{5}{4}-\dfrac{7}{5}=\dfrac{3}{10}\)
g: \(x=9-\dfrac{8}{7}-\dfrac{7}{8}=\dfrac{391}{56}\)
