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Y=1-3x
x²+x(1-3x)+(1-3x)²=3
x²+x-3x²+1-6x+9x²-3=0
7x²-5x-2=0
D= 25+56=81
x1= (5+9)/14=1
x2=(5-9)/14=-2/7
y1=1-3= -2
y2=1+6/7= 13/7=1 6/7
ответ: (1;-2), (-2/7, 1 6/7)
(a + b)^2 = 36, (a + b)^2 = (+-6)^2, a + b = +-6
a^2 - b^2 = 24 = (a + b)(a - b) ===> a - b = +-4
(a - b)^2 = (+-4)^2 = 16
Ответ. 16.