Question

Determinați numerele reale x care verifică egalitățile :
a) |x-1| = 3
b) |x-3| = 7
c) 2|x-3| - 13 = 25.
Dau coroana!

Answer 1

$a) |x - 1| = 3$

$1)x - 1 = 3$

$x = 3 + 1$

$x = 4$

$2) - x + 1 = 3$

$- x = 3 - 1$

$- x = 2 \: | \times ( - 1)$

$x = - 2$

$b) |x - 3| = 7$

$1)x - 3 = 7$

$x = 7 + 3$

$x = 10$

$2) - x + 3 = 7$

$- x = 7 - 3$

$- x = 4 \: | \times ( - 1)$

$x = - 4$

$3)2 |x - 3| - 13 = 25$

$2 |x - 3| = 25 + 13$

$2 |x - 3| = 38 \: | \div 2$

$|x - 3| = 19$

$1)x - 3 = 19$

$x = 19 + 3$

$x = 22$

$2) - x + 3 = 19$

$- x = 19 - 3$

$- x = 16 \: | \times ( - 1)$

$x = - 16$