18 x y- y : 0,125 +y x 0,5 - 2 x y x 0,15 =18
18 x y - y x 8 + y x 0,5 - y x 0,3 =18
y x (18-8+0,5-0,3)=18
y x 10,2=18
y= \(\frac{30}{17}\)
\(18\times y-y:0,125+y\times0,5-2\times y\times0,15=18\)
\(\Rightarrow18\times y-y\times8+y\times\frac{5}{10}-2\times y\times0,15=18\)
\(\Rightarrow18\times y-y\times8+y\times\frac{1}{2}-2\times y\times\frac{15}{10}=18\)
\(\Rightarrow18\times y-y\times8+y\times2-2\times y\times\frac{3}{2}=18\)
Tự tìm nhé