3.
( 2 + 1 ) : 1 = 2 + 6
(х²-9 3х-х²) 2х²+12х+18 х
По действиям:
2 + 1 = 2 - 1 = 2 - 1 =
x²-9 3x-x² (x-3)(x+3) x²-3x (x-3)(x+3) x(x-3)
= 2x - (x+3) = 2x-x-3 = x-3 = 1
x(x-3)(x+3) x(x-3)(x+3) x(x-3)(x+3) x(x+3)
2) 1 = 1 = 1
2x²+12x+18 2(x²+6x+9) 2(x+3)²
3) 1 : 1 = 1 * 2(x+3)² = 2(x+3) = 2x+6 = 2+ 6
x(x+3) 2(x+3)² x(x+3) 1 x x x
5. y= 16-5x
3
16-5x >0
3
16-5x>0
-5x>-16
x<16/5<br>x<3,2<br>Ответ: x<3,2