Ответ:

[tex]2x - 6 = 45 \\ 2x = 45 + 6 \\ 2x = 51 \\ x = 25.5[/tex]

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[tex](x - 4) \div 3 = 5 \\ x - 4 = 5 \times 3 \\ x - 4 = 15 \\ x = 4 + 15 \\ x = 19[/tex]

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[tex](x - 7) \div x = 0 \\ x - 7 = 0 \times x \\ x - 7 = 0 \\ x = 7[/tex]

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[tex] \frac{1}{3} x - 2 = 5 \\ \\ \frac{1}{3} x = 5 + 2 \\ \\ \frac{1}{3} x = 7 \\ \\ x = 7 \div \frac{1}{3} [/tex]

[tex]x = 7 \times 3 \\ x = 21[/tex]

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