Biz \(x\) ni bizga kerak bo'ladigan 14% eritma miqdori bo'lishiga ruxsat berishdan boshlaymiz. Bu, o'z navbatida, bizga \(100 - x\)gallon 60% eritma kerak bo'ladi.

Keyin asosiy so'z tenglamasi,

\[\left( \begin{array}{c}{\mbox{Amount of salt}}\\ {\mbox{in 14% solution}}\end{array} \right) + \left( \begin{array}{c}{\mbox{Amount of salt}}\\ {\mbox{in 60% solution}}\end{array} \right) = \left( \begin{array}{c}{\mbox{Amount of salt}}\\ {\mbox{in 25% solution}}\end{array} \right)\]

Biz bilamizki, eritmadagi tuz miqdori = Eritmaning foizi X Eritma hajmi. Bu quyidagi so'z tenglamasini beradi.

\[\left( {0.14} \right)\left( \begin{array}{c}\,\,{\mbox{Volume of}}\\ {\mbox{14% solution}}\end{array} \right) + \left( {0.6} \right)\left( \begin{array}{c}\,\,{\mbox{Volume of}}\\ {\mbox{60% solution}}\end{array} \right) = \left( {0.25} \right)\left( \begin{array}{c}\,\,{\mbox{Volume of}}\\ {\mbox{25% solution}}\end{array} \right)\]

2-qadam

Shunday qilib, barcha ma'lum ma'lumotlarni ulash \(x\) uchun hal qilishimiz mumkin bo'lgan quyidagi tenglamani beradi.

\[\begin{align*}0.14x + 0.6\left( {100 - x} \right) & = 0.25\left( {100} \right)\\ 0.14x + 60 - 0.6x & = 25\\ - 0.46x & = - 35\\ x & = 76.09\end{align*}\]

Shunday qilib, bizga 76,09 litr 14% tuz eritmasi va 23,91 litr 60% tuz eritmasi kerak bo'ladi.