a, \(\dfrac{14}{5}.x-50=34\\ =>\dfrac{14}{5}.x=34+50=84\\ =>x=84:\dfrac{14}{5}=30\)
b, \(\left(25\%-2\dfrac{1}{2}\right).2x-\dfrac{5}{4}.2^4=\dfrac{525}{100}\\ < =>\left(\dfrac{1}{4}-\dfrac{5}{2}\right).2x-\dfrac{5}{4}.16=\dfrac{525}{100}\\ < =>-\dfrac{9}{4}.2x-20=\dfrac{525}{100}\\ < =>-\dfrac{9}{2}x-20=\dfrac{525}{100}\\ =>-\dfrac{9}{2}x=\dfrac{525}{100}+20=\dfrac{101}{4}\\ =>x=\dfrac{\dfrac{101}{4}}{-\dfrac{9}{2}}=-\dfrac{101}{18}\)
a) \(\dfrac{14}{5}.x-50=34\)
\(\dfrac{14}{5}.x=34+50\)
\(\dfrac{14}{5}.x=84\)
\(x=84:\dfrac{14}{5}=84.\dfrac{5}{14}\)
\(x=30\)
Vậy: ....
b) \(\left(25\%-2\dfrac{1}{2}\right).2x-\dfrac{5}{4}.2^4=\dfrac{525}{100}\)
\(\left(\dfrac{1}{4}-\dfrac{5}{2}\right).2x-\dfrac{5}{4}.16=\dfrac{21}{4}\)
\(-\dfrac{9}{4}.2x-20=\dfrac{21}{4}\)
\(-\dfrac{9}{2}x-20=\dfrac{21}{4}\)
\(-\dfrac{9}{2}x=20+\dfrac{21}{4}\)
\(-\dfrac{9}{2}x=\dfrac{101}{4}\)
\(x=\dfrac{101}{4}:-\dfrac{9}{2}=\dfrac{101}{4}.-\dfrac{2}{9}\)
\(x=-\dfrac{101}{18}\)
Vậy:...
