[tex]2 \times + 5 + \times - 2 = 12 \\ 3 \times = 12 - 5 + 2 \\ 3 \times = 9 | \div 3| \\ \times = 3[/tex]
[tex]4 \times + 7 - \times + 2 - 9 \\ 3 \times = 9 - 7 - 2 \\ 3 \times = 0 | \div 3 \\ \times = 0| [/tex]
[tex] - 3 \times - 1 + 5 \times + 7 = 0 \\ 2 \times = 0 + 1 - 7 \\ 2 \times = - 6 | \div 2 \\ \times = - 3| [/tex]
