[tex]4x = 20\\x = 20 :4\\x = 5\\\\\frac{2}{3} x = 9\\\\x = 9 : \frac{2}{3} \\x = 9 * \frac{2}{3} \\x = 6\\\\-3x = 8\\x = \frac{8}{-3} \\x = -2 \frac{2}{3} \\\\3x + 4 = 13\\3x = 13 - 4\\3x = 9 |:3\\x = 3[/tex]
[tex]5x - 4 = 6\\5x = 4 + 6\\5x = 10 |:5\\x = 2\\\\3(x+5) = 21\\3x + 15 = 21\\3x = 21-15\\3x = 6 |:3\\x = 2\\\\4(x-1) = 16\\4x - 4 = 16\\4x = 16+4\\4x = 20 |:4\\x = 5\\\\3x + 4 = 2x + 7\\3x - 2x = 7 - 4\\x = 3\\\\5x - 2 = 3x + 4\\5x - 3x = 4 + 2\\2x = 6 |:2\\x = 3\\\\2(x+1) + 3(x+2) = 4\\2x + 2 + 3x + 6 = 4\\5x = 4 - 8\\5x = -4 |:5\\x = - \frac{4}{5}[/tex]
