1) 19+5x>=0 x>=-3.8
2)14+5x>=0 x>=-2,8
3) 2-x-x^2>=0
x^2+x-2<=0
[-2;1]
√2 * √8 = √(2 * 8) = √16 = 4,
√2 / √18 = √(2/18) = √(1/9) = 1/3,
√27 * √3 = √(27 * 3) = √81 = 9,
√52 / √117 = √(52/117) = √(4/9) = 2/3