1) (a) 1/6√255+2.1√0.49=√255/6+2.1√49/100=√255/6+2.1*7/10=√255/6+2.1*0.7=√255/6+1.47=4.13145
(б) 1-6√1/4=1-6*1/2=1-3= -2
(в) (3√0.8)^2=(3√8/10)^2=(3√4/5)^2=(3*√4/√5)^2=(3*2/√5)^2=(6/√5)^2=(6√5/5)^2=36*5/25=36/5=7.2
3) (a)x^2=0.81
x=+-9/10
x=9/10
x= -9/10
x один = 9/10, x два = -9/10
(б) (a)x^2=56
x=+-2√14
x=2√14
x= -2√14
x один = 2√14, x два = -2√14