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
5х^2-15=0
5х^2=15
х^2=3
х=+/-√3
<span>(1-2х)^3-12х^2+8х^3=0
-(2x-1)</span>³-12x²+8x³=0
-(8x³-12x²+6x-1)-12x²+8x³=0
-8x³+12x²+6x-1)-12x²+8x³=0
-6x+1=0
-6x=-1
6x=1
x=1÷6
x=1/6
Подставляем общие множители: для 1-ой дроби (m+n), для 2-ой (m²(m+n)), для 3 (m²). И получается:
=
=
сокращаем m+n =
=