[tex]a) \frac{2x + 1}{5} \: echiunitara[/tex]
[tex] 2x + 1 = 5[/tex]
[tex]2x = 5 - 1[/tex]
[tex]2x = 4[/tex]
[tex]x = \frac{4}{2} [/tex]
[tex]x = 2[/tex]
[tex]b) \frac{12 - 3x}{3} \: echiunitara[/tex]
[tex]12 - 3x = 3[/tex]
[tex] - 3x = 3 - 12[/tex]
[tex] - 3x = - 9 \: | \div ( - 3)[/tex]
[tex]x = 3[/tex]
[tex]c) \frac{18 \div x - 1}{2} \: echiunitara[/tex]
[tex]18 \div x - 1 = 2 \: | \times x[/tex]
[tex]18 - x= 2x[/tex]
[tex] - x - 2x = - 18[/tex]
[tex] - 3x = - 18 \: | \div ( - 3)[/tex]
[tex]x = 6[/tex]
[tex]d) \frac{x \div 5 + 18}{43} \: echiunitara[/tex]
[tex]x \div 5 + 18 = 43 \: | \times 5[/tex]
[tex]x + 90 = 215[/tex]
[tex]x = 215 - 90[/tex]
[tex]x = 125[/tex]
[tex]e) \frac{[(123 - x) \times 3 + 5] \div 2}{19} \: echiunitara[/tex]
[tex][(123 - x) \times 3 + 5] \div 2 = 19 \: | \times 2[/tex]
[tex](123 -x ) \times 3 + 5 = 38[/tex]
[tex](123 - x) \times 3 = 38 - 5[/tex]
[tex](123 - x) \times 3 = 33 \: | \div 3[/tex]
[tex]123 - x = 11[/tex]
[tex] - x = 11 - 123[/tex]
[tex] - x = - 112 \: | \times ( - 1)[/tex]
[tex]x = 112[/tex]
[tex]f) \frac{175 - [(x \div 7 + 8) \div 3 + 40] \div 9}{4 \times 20 + 30 \times 3} \: echiunitara[/tex]
[tex]175 - [(x \div 7 + 8) \div 3 + 40] \div 9 = 4 \times 20 + 30 \times 3[/tex]
[tex]175 - [(x \div 7 + 8) \div 3 + 40] \div 9 = 80 + 90[/tex]
[tex]175 - [(x \div 7 + 8) \div 3 + 40] \div 9 = 170[/tex]
[tex] - [(x \div 7 + 8) \div 3 + 40] \div 9 = 170 - 175[/tex]
[tex] - [(x \div 7 + 8) \div 3 + 40] \div 9 = - 5 \: | \times ( - 1)[/tex]
[tex][(x \div 7 + 8) \div 3 + 40] \div 9 = 5 \: | \times 9[/tex]
[tex](x \div 7 + 8) \div 3 + 40 = 45[/tex]
[tex](x \div 7 + 8) \div 3 = 45 - 40[/tex]
[tex](x \div 7 + 8) \div 3 = 5 \: | \times 3[/tex]
[tex]x \div 7 + 8 = 15[/tex]
[tex]x \div 7 = 15 - 8[/tex]
[tex]x \div 7 = 7[/tex]
[tex]x = 7 \times 7[/tex]
[tex]x = 49[/tex]
