1/7<x<1/8
1/7 ≈ 0,142
1/8≈ 0,125
х = любое число от 0,126 до 0,141
X + y = 6
xy = - 3
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x = 6 - y
y( 6 - y ) = - 3
6y - y^2 = - 3
y^2 - 6y - 3 = 0
D = 36 + 12 = 48
√ D = √ 48 = 4 √ 3
y1 = ( 6 + 4 √ 3 ) : 2 = 3 + 2 √ 3
y2 = 3 - 2 √ 3
x = 6 - y
x1 = 6 - ( 3 + 2 √ 3 ) = 3 - 2 √ 3
x2 = 6 - ( 3 - 2 √ 3 ) = 3 + 2 √ 3
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x^4 = ?
1) ( 3 - 2 √ 3 )^4 = ?
( 3 - 2 √ 3 )^2 = 9 - 12*3 + 4*3 = 9 - 36 + 12 = - 15
( 3 - 2 √ 3 )^4 = - 15 * ( - 15 ) = 225
2) ( 3 + 2 √ 3 )^2 = 9 + 12*3 + 4*3 = 9 + 36 + 12 = 57
( 3 - 2 √ 3 )^4 = 57 * 57 = 3249
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1) X^4 + y^4 = 225 + 3249 = 3474
2) X^4 + y^4 = 57 + 225 = 282
3,07*2,11-0,66+2,11*2,93=12
1)3,07*2,11=6,4777
2)2,11*2,93=6,1823
3)6,4777-0,66=5,8177
4)5,8177+6,1823=12
ответ 12
X^(1/4)=p, y^(1/4)=q,
(2/(p-q)+2/(p+q))*(1/p^2-1/q^2)*p*q^2/6
=-(4p/(p^2-q^2))(p^2-q^2)pq^2/
(6p^2q^2)=-4/6=-2/3