1)5х^2+3х<8 х(5х+3)<8 х<8 5х+3<8 5х<8-3 5х<5 х<1 2)7(6х^2+2x+1)>=0 42x^2+14x+7>=0 14x(3x+1)>=-7 14x>=-7 3x>=-8 x>=-0.5 x>=-2.6