40% x X + 20% = 72
=>2/5 x X +1/5 =72
2/5 x X = 72 - 1/5
2/5 x X = 359/5
X=359/2
X=179,5
40%xX+20%=72
=> \(\frac{2}{5}xX+\frac{1}{5}=72\)
=> \(\frac{2}{5}xX=72-\frac{1}{5}=\frac{359}{5}\)
=> \(X=\frac{359}{5}:\frac{2}{5}=\frac{359}{2}\)
tích nha !
\(40\%=\frac{40}{100}=\frac{4}{10}=\frac{2}{5}xX+20\%=\frac{20}{100}=\frac{2}{10}=\frac{1}{5}=72\)72
\(\frac{2}{5}xX+\frac{1}{5}=72\)
\(\frac{2}{5}xX=72-\frac{1}{5}\)
\(\frac{2}{5}xX=\frac{360}{5}-\frac{1}{5}\)
\(\frac{2}{5}xX=\frac{359}{5}\)
\(X=\frac{359}{5}:\frac{2}{5}\)
\(X=\frac{359}{5}x\frac{5}{2}\)
\(X=\frac{359}{2}\)
40% x X +20% = 72
=> 40/100 x X +20/100 = 72
=> 2/5 x X +1/5 = 72 ( nếu chưa hiểu thì tui giải thich la 2/5 la khi rút gọn 40/100 va 1/5 la khi rút gọn 20/100 )
=> 2/5 x X = 72-1/5
=> 2/5x X = 359/5
=> X = 359/5 : 2/5
=> X = 259/2 (nếu mà cô giáo bắt viết thành phần trăm thi la 12950% nha)
dau can phai tra loi dai dong nhu the