40/100 x X + X x 20/100 = 72
2/5 x X + X x 1/5 = 72
X x ( 2/5 + 1/5 ) = 72
X x 3/5 = 72
X = 72 : 3/5
X = 120
Trả lời :
40%*X+X*20%=72
\(40\%\) \(.\)\(x\) \(+\) \(x\) \(.\) \(\frac{20}{100}\)\(=\)\(72\)
\(\frac{40}{100}\)\(.\)\(x\)\(+\)\(x\)\(\frac{1}{5}\)\(=\)\(72\)
\(x\)\(.\)\(\left(\frac{2}{5}+\frac{1}{5}\right)\)\(=\)\(72\)
\(x\)\(.\)\(\frac{3}{5}\)\(=\) \(72\)
\(x\)\(=\) \(72\)\(:\)\(\frac{3}{5}\)
\(x\)\(=\) \(120\)
40% * X + X * 20% = 72
X * (40% + 20%) = 72
X * 60% = 72
X * 0,6 = 72
X = 72 : 0,6
X = 120