a)42x-7-2(x²+6x+9)<3(x²+4x+4)-5(x²-2x+1) 42x-7-2x²-12x-18<3x²+12x+12-5x²+10x-5 30x-12x-10x<7+7+18 8x<32 /:8 x<4 b)1+12x+36x²+4+32x+64x²≥1+20x+100x² 44x-20x≥1-1-4 24x≥-4 /:24 x≥⅙ c)7,5x²-5x-(0,25x²+x+1)-8x<7,25x²+6 7,5x²-5x-0,25x²-x-1-8x<6 -14x<6+1 -14x<7 /:(-14) x>-½ d)1,69x²+7,8x+9-1,69x²-8,45+0,75≥0 7,8x≥-1,3 /:7,8 x≥⅙ proszę o naj ;) pozdrawiam :)
a) 7(6x-1)-2(x+3)²<3(x+2)²-5(x-1)² 42x - 7 -2(x² +6x +9) < 3(x² +4x + 4) -5(x² - 2x +1) 42x - 7 -2x² -12x - 18 < 3x² +12x + 12 -5x² +10x -5 42x-12x -12x -10x < 12 -5 +7 +18 8x < 32 x < 4 b) (1+6x)²+(2+8x)²≥(1+10x)² 1 + 12x + 36x² + 4 + 32x + 64x² ≥ 1 + 20x + 100x² 12x + 32x -20x ≥ 1 -1 -4 24x ≥ -4 x ≥ -1/6 c) 2,5x(3x-2)-(0,5x+1)²-8x < 7,25x²+6 7,5x² -5x - 0,25x² -x - 1 -8x < 7,25x² + 6 7,5x² -0,25x² -5x -x - 8x - 7,25x² < 6+1 -14x < 7 x > -1/2 d) (1,3x+3)²-1,69x(x+5)+0,75 ≥ 0 1,69x² + 7,8x +9 -1,69x² -8,45x +0,75 ≥ 0 7,8x - 8,45x ≥ -9,75 0,65x ≥ -9,75 x ≤ 15