Solve[br][br][math] \begin{cases}\begin{align}[br]0.6x-0.2y-1.2&=0\\[br]-1.2x+0.4y-3.6&=0\\[br]\end{align}\end{cases}[/math][br] [br]We can rewrite equations in the standard form. At the same time, both equations are multiplied with 10 to get rid of decimal numbers:[br][br][math] \begin{cases}\begin{align}[br] 6x- 2y&=12\\[br]-12x+4y&=36\\[br]\end{align}\end{cases}[/math][br][br]Multiply equations so that you have opposite numbers at least for one variable:[br][br][math] \begin{cases}\begin{align}[br] 12x- 4y&=24\\[br]-12x+4y&=36\\[br]\end{align}\end{cases}[/math][br] [br]As seen, the sum of equations is 0 = 60. This statement is not true, so there is no solution.  [br][br]