Question

Решите неравенства 35.11. 1) (x+8)-x < 11x; 3) (12+ x)² > x² +21x; 2) x² - (9-x)³ > -2x; 4) x² < (25-x)² + 25x. 2)-241² + (8-1)³ 13
даю 25 баллов​

Answer 1

Ответ:

1)

$(x + 8) - x < 11x$

$x + 8 - x < 11x$

$8 < 11x$

$11x > 8$

$11x - 11 > 8 \div 11$

$x > 8 \div 11$

$x > \frac{8}{11}$

3)

$(12 + x) ^{2} > x ^{2} + 21x$

$12 ^{2} + 2 \times 12x + x ^{2}$

$144 + 24x + x ^{2} > x ^{2} + 21x$

$144 + 24x > 21x$

$144 + 24x - 144 > 21x - 144$

$24x > 21x - 144$

$24x - 21x > - 144$

$(24 - 21)x$

$3x > - 144$

$3x \div 3 > - 144 \div 3$

$x > - 144 \div 3$

$x > - 48$