Question

Am mare nevoie de ajutor! Va rog mult, dau coroana ! ​

Answer 1

$a)5 \times x - 15 = 0$

$5x = 0 + 15$

$5x = 15 \: | \div 5$

$x = 3 \: \in \: \mathbb{Z}$

$b)4 \times x + 16 = 20$

$4x = 20 - 16$

$4x = 4 \: | \div 4$

$x = 1 \: \in \: \mathbb{Z}$

$c) - 3 \times x + 11 = - 1$

$- 3x = - 1 - 11$

$- 3x = - 12 \: | \div ( - 3)$

$x = 4 \: \in \: \mathbb{Z}$

$d) - 2 \times x - 200 = 0$

$- 2x = 0 + 200$

$- 2x = 200 \: | \div ( - 2)$

$x = - 100 \: \in \: \mathbb{Z}$

$e)21 = 7 \times x - 21$

$21 = 7x - 21$

$7x - 21 = 21$

$7x = 21 + 21$

$7x = 42 \: | \div 7$

$x = 6 \: \in \: \mathbb{Z}$

$f)10 \times x + 99 = 88$

$10x = 88 - 99$

$10x = - 11$

$x = - \frac{11}{10} \: \notin \: \mathbb{Z}$

$g)2 \times x + x = - 20 + ( - 10)$

$2x + x = - 20 - 10$

$3x = - 30 \: | \div 3$

$x = - 10 \: \in \: \mathbb{Z}$

$h) - (1 - 2x) = - 37$

$- 1 + 2x = - 37$

$2x = - 37 + 1$

$2x = - 36 \: | \div 2$

$x = - 18 \: \in \: \mathbb{Z}$