Question

Determinati x € Q oentru care |2x+3|=0,8 (3)

Answer 1

$|2x + 3| = 0.8(3)$

$|2x + 3| = \frac{83 - 8}{90}$

$|2x + 3| = \frac{75}{90}$

$|2x + 3| = \frac{15}{18}$

$|2x + 3| = \frac{5}{6}$

$1)2x + 3 = \frac{5}{6} \: | \times 6$

$12x + 18 = 5$

$12x = 5 - 18$

$12x = - 13$

$x = - \frac{13}{12}\:\in\:\mathbb{Q}$

$2) - 2x - 3 = \frac{5}{6} \: | \times 6$

$- 12x - 18 = 5$

$- 12x = 5 + 18$

$- 12x = 23 \: | \times ( - 1)$

$12x = - 23$

$x = - \frac{23}{12}\:\in\:\mathbb{Q}$