## Algebra and Trigonometry 10th Edition

$|x-7|\geq3$
$|u|\lt a~↔~-a\lt u\lt a$ $|u|\leq a~↔~-a\leq u\leq a$ $|u|\gt a~↔~u\lt-a~or~u\gt a$ $|u|\geq a~↔~u\leq-a~or~u\geq a$ The numbers must be greater or equal to 10 or less than or equal to 4: $x\leq4$ or $x\geq10$ $x-7\leq4-7$ or $x-7\geq10-7$ $x-7\leq-3$ or $x-7\geq3$ $|x-7|\geq3$