Ex 4 Punctele B,C,D.

b) x²+2x+1-x²+6x-9≥x²-2x+1-x²+4x-4
8x²-8≥2x-3
8x-2x≥8-3
6x≥5, x≥5/6
c) 8x +8 -4x+12 <3x +36
4x +20<3x +36
4 x - 3x < 36-20
x < 16
d)( x+2)² - 3 (x+4) > (x+3)(x-5)-2
x² +4x +4-3x -12 > x²-5x+3x-15-2
x²+x-8>x²-2x-17
x²+x-x²+2x>8-17
3x>-19
x> 19/3