Câu hỏi của Bộ 3 bất tử

Question

tìm x

a 13+x/20 = 3/4 b 23-x/25 = 4/5

Park Jimin - Mai Thanh Hoa · Accepted Answer

$13+\frac{x}{20}=\frac{3}{4}\Leftrightarrow\frac{x}{20}=\frac{3}{4}-13\Leftrightarrow\frac{x}{20}=-12\frac{1}{4}$

$\Leftrightarrow\frac{x}{20}=-\frac{49}{4}\Leftrightarrow4x=20\cdot\left(-49\right)\Leftrightarrow4x=-980$

$\Leftrightarrow x=\left(-980\right):4\Leftrightarrow x=-245$

$23-\frac{x}{25}=\frac{4}{5}\Leftrightarrow\frac{x}{25}=23-\frac{4}{5}\Leftrightarrow\frac{x}{25}=22\frac{1}{5}$

$\Leftrightarrow\frac{x}{25}=\frac{111}{5}\Leftrightarrow5x=25\cdot111\Leftrightarrow5x=2775$

$\Leftrightarrow x=2775:5\Leftrightarrow x=555$

Câu trả lời:

$13+\frac{x}{20}=\frac{3}{4}\Leftrightarrow\frac{x}{20}=\frac{3}{4}-13\Leftrightarrow\frac{x}{20}=-12\frac{1}{4}$

$\Leftrightarrow\frac{x}{20}=-\frac{49}{4}\Leftrightarrow4x=20\cdot\left(-49\right)\Leftrightarrow4x=-980$

$\Leftrightarrow x=\left(-980\right):4\Leftrightarrow x=-245$

$23-\frac{x}{25}=\frac{4}{5}\Leftrightarrow\frac{x}{25}=23-\frac{4}{5}\Leftrightarrow\frac{x}{25}=22\frac{1}{5}$

$\Leftrightarrow\frac{x}{25}=\frac{111}{5}\Leftrightarrow5x=25\cdot111\Leftrightarrow5x=2775$

$\Leftrightarrow x=2775:5\Leftrightarrow x=555$

Nguyễn Ngọc Cường · Answer

a)13+x/20=3/4 b)23-x/25=4/5

x/20=3/4-13 x/25=23-4/5

x/20=-12,25 x/25=22,2

x=-245 x=555

Câu trả lời:

a)13+x/20=3/4 b)23-x/25=4/5

x/20=3/4-13 x/25=23-4/5

x/20=-12,25 x/25=22,2

x=-245 x=555

Hoshimiya Ichigo · Answer

a) x= -245

b)x= 595

Câu trả lời:

a) x= -245

b)x= 595