Question

Resolver las siguientes ecuaciones y hacer la comprobación

Answer 1

Respuesta:

$7x - 15 = 20 \\ 7x = 20 + 15 \\ 7x = 35 \\ x = 5 \\ \\ Comprobación \\ 7 \times 5 - 15 = 20 \\ 35 - 15 = 20 \\ 20 = 20$

$- 5x - 8 = 12 \\ - 8 - 12 = 5x \\ - 20 = 5x \\ - 4 = x \\ \\ Comprobación \\ - 5 \times ( - 4) - 8 = 12 \\ 20 - 8 = 12 \\ 12 = 12$

$4x - 10 = 26 \\ 4x = 26 + 10 \\ 4x = 36 \\ x = 9 \\ \\ Comprobación \\ 4 \times 9 - 10 = 26 \\ 36 - 10 = 26 \\ 26 = 26$

$9x - 4 = 2x \\ 9x - 2x = 4 \\ 7x = 4 \\ x = \frac{4}{7} \\ \\ Comprobación \\ 9 \times \frac{4}{7} - 4 = 2 \times \frac{4}{7} \\ \frac{36}{7} - 4 = \frac{8}{7} \\ \frac{36}{7} - \frac{28}{7} = \frac{8}{7} \\ \frac{8}{7} = \frac{8}{7}$

$x + 5x = - 10 + 3 \\ 6x = - 7 \\ x = - \frac{7}{6} \\ \\ Comprobación \\ - \frac{7}{6} + 5 \times ( - \frac{7}{6} ) = - 10 + 3 \\ - \frac{7}{6} + ( - \frac{35}{6} ) = - 7 \\ - \frac{42}{6} = - 7 \\ - 7 = - 7$

$7(x - 5) - x = 3 \\ 7x - 35 - x = 3 \\ 6x - 35 = 3 \\ 6x = 3 + 35 \\ 6x = 38 \\ x = \frac{38}{6} \\ x = \frac{19}{3} \\ \\ Comprobación \\ 7( \frac{19}{3} - 5 ) - \frac{19}{3} = 3 \\ 7( \frac{19}{3} - \frac{15}{3} ) - \frac{19}{3} = 3 \\ 7 \times \frac{4}{3} - \frac{19}{3} = 3 \\ \frac{28}{3} - \frac{19}{3} = 3 \\ \frac{9}{3} = 3 \\ 3 = 3$

$- 3(2x - 5) - 5x = 3x \\ - 6x + 15 - 5x = 3x \\ - 11x + 15 = 3x \\ 15 = 3x + 11x \\ 15 = 14x \\ \frac{15}{14} = x \\ \\ Comprobación \\ - 3(2 \times \frac{15}{14} - 5) - 5 \times \frac{15}{14} = 3 \times \frac{15}{14} \\ - 3( \frac{15}{7} - 5 ) - \frac{75}{14} = \frac{45}{14} \\ - \frac{45}{7} + 15 - \frac{75}{14} = \frac{45}{14} \\ - \frac{90}{14} + \frac{210}{14} - \frac{75}{14} = \frac{45}{14} \\ \frac{45}{14} = \frac{45}{14}$

$7(x - 2) + 6x + 1 = 3 - 4x \\ 7x - 14 + 6x + 1 = 3 - 4x \\ 13x - 13 = 3 - 4x \\ 13x + 4x = 3 + 13 \\ 17x = 16 \\ x = \frac{16}{17} \\ \\ Comprobación \\ 7( \frac{16}{17} - 2) + 6 \times \frac{16}{17} + 1 = 3 - 4 \times \frac{16}{17} \\ 7( \frac{16}{17} - \frac{34}{17} ) + \frac{96}{17} + 1 = 3 - \frac{64}{17} \\ 7 \times ( - \frac{18}{17} ) + \frac{96}{17} + 1 = \frac{51}{17} - \frac{64}{17} \\ - \frac{126}{17} + \frac{96}{17} + \frac{17}{17} = - \frac{13}{17} \\ - \frac{13}{17} = - \frac{13}{17}$