Aufgaben zum Durchführen der Äquivalenzumformungen rückwärts

$\def\arraystretch{1.25} \begin{array}{rcl} 2x - \boxed{\phantom {2x}}&=&-8x + 22\\ \\ \phantom{2x -}\boxed{\phantom {2x}}&=&-8x+30\\ \\ 10x &=&\boxed{\phantom {2x}}\\ \\ x&=& 3 \end{array}$

$\def\arraystretch{1.25} \begin{array}{rcl} 9x + \boxed{\phantom {2x}}&=& \boxed{\phantom {2x}} + 30\\ \\ \phantom{2x -}\boxed{\phantom {2x}}&=&10x+3\\ \\ \boxed{\phantom {2x}} &=& 3\\ \\ x&=& -3 \end{array}$

$\def\arraystretch{1.25} \begin{array}{rcl} \boxed{\phantom {2x}}+22x+63&=&\boxed{\phantom {2x}} + 28+ \boxed{\phantom {2x}}\\ \\ 5x+100&=&\phantom{}\boxed{\phantom {2x}}\\ \\ \boxed{\phantom {2x}} &=& 6\\ \\ x&=& 1{,}2 \end{array}$