Câu hỏi của Phạm Vũ Minh Anh

Question

Tìm x biết:

a) $\dfrac{14}{5}.x-50=34$

b) $\left(25\%-2\dfrac{1}{2}\right).2x-\dfrac{5}{4}.2^4=\dfrac{525}{100}$

Nguyễn Trần Thành Đạt · Accepted Answer

a, $\dfrac{14}{5}.x-50=34\ =>\dfrac{14}{5}.x=34+50=84\ =>x=84:\dfrac{14}{5}=30$

b, $\left(25\%-2\dfrac{1}{2}\right).2x-\dfrac{5}{4}.2^4=\dfrac{525}{100}\ < =>\left(\dfrac{1}{4}-\dfrac{5}{2}\right).2x-\dfrac{5}{4}.16=\dfrac{525}{100}\ < =>-\dfrac{9}{4}.2x-20=\dfrac{525}{100}\ < =>-\dfrac{9}{2}x-20=\dfrac{525}{100}\ =>-\dfrac{9}{2}x=\dfrac{525}{100}+20=\dfrac{101}{4}\ =>x=\dfrac{\dfrac{101}{4}}{-\dfrac{9}{2}}=-\dfrac{101}{18}$

Câu trả lời:

a, $\dfrac{14}{5}.x-50=34\ =>\dfrac{14}{5}.x=34+50=84\ =>x=84:\dfrac{14}{5}=30$

b, $\left(25\%-2\dfrac{1}{2}\right).2x-\dfrac{5}{4}.2^4=\dfrac{525}{100}\ < =>\left(\dfrac{1}{4}-\dfrac{5}{2}\right).2x-\dfrac{5}{4}.16=\dfrac{525}{100}\ < =>-\dfrac{9}{4}.2x-20=\dfrac{525}{100}\ < =>-\dfrac{9}{2}x-20=\dfrac{525}{100}\ =>-\dfrac{9}{2}x=\dfrac{525}{100}+20=\dfrac{101}{4}\ =>x=\dfrac{\dfrac{101}{4}}{-\dfrac{9}{2}}=-\dfrac{101}{18}$

Phạm Vũ Minh Anh · Answer

bạn có thể ghi cho mình rõ hơn một chút đi nhưng k sao cảm ơn bạnNguyễn Trần Thành Đạt nha

Câu trả lời:

bạn có thể ghi cho mình rõ hơn một chút đi nhưng k sao cảm ơn bạnNguyễn Trần Thành Đạt nha

Anh Triêt · Answer

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:...

Câu trả lời:

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:...

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