Ответы и объяснения

2014-02-19T13:56:59+00:00
1) D=15^2-4*9*(-69)=225+2484=2709
X1=-15+52,048 / 2*9 = 37,048 /18 = 2,058
X2= -15 - 52,048 / 2*9 = -67,048/18= - 3,727

2) D=5^2-4*3*(-8) = 25+96= 121
X1= - 5+11 / 2*3 = 6/6 = 1 
X2= -5-11 / 2*3 = -16/6 = -2,667