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A=D(54)={1,2,3,6,9,18,27,54}
B=D(63)={1,3,7,21,63}
A∩B={1,3}
A∪B={1,2,3,6,7,9,18,21,37,54,63}
X^2 - 16x+64-x^2-4x+4x+16=0
-16x=-80
X=5
Ах + by = 5
ax + 3y = 7 - b
X = 4
y = - 2
Решение
4а - 2b = 5
4a - 6b = 7 - b
- 4a + 6b = b - 7
4b = b - 2
3b = - 2
b = - 2/3
4a - 2( - 2/3 ) = 5
4a = 5 + ( 4/3 )
4a = 19/3
a = 19/12
a = 1 7/12
Ответ ( 1 7/12 ; - 2/3 )
<span>если x-y = √7-3
,</span><span> √7-3=√7-√9<0, значит х< y
</span>