X+5+=138
X=138-54
X=84
538-x=269
X=538-269
X=269
X-86=57
X=57+86
X=143
723-(x+238)=345
X+238=723-345
X+238=378
X=378-238
X=140
2х²-11х+13=0
х²-5,5х+6,5=0⇒х1+х2=5,5 и х1*х2=6,5
(х1)³+(х2)³=(х1)+(х2))((х1)²-(х1)(х2)+(х1)²)=((х1)+(х2)((х1)+(х2))²-3(х1)(х2))
=5,5*(5,5²-3*6,5)=5,5*(30,25-19,5)=5,5*10,75=59,125
((х1)+(х2)²=(х1)²+2(х1)(х2)+(х2)²⇒(х1)²+(х2)²=((х1)+(х2))²-2(х1)(х2)
3(x^2 + 2x + 1) = 2x + 2
3x^2 + 6x + 3 = 2x + 2
3x^2 + 4x + 1 = 0
D = 4^2 - 4 * 3 * 1 = 16 - 12 = 4
√D = √4 = 2
x1 = (-4 + 2) / 6 = -2 / 6 = - 1/3
x2 = (-4 - 2) / 6 = - 6 / 6 = -1
Ответ: -1.
<span>(x + 3)(x - 1) = 2x(x - 2) + 5
...
x^2 - 6x + 8 = 0
D = 6^2 - 4*1*8 = 36 - 32 = 4
</span>√D = √4 = 2
<span>x1 = (6 + 2) / 2 = 8 / 2 = 4
x2 = (6 - 2) / 2 = 4 / 2 = 2
Ответ: 2.
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