E^x*cos(x)-e^x*sin(x)+3*sqrt(2)*x^2
(a+5)²-(a-3)²=a²+10a+25-a²+9a-9=19a+16
(x-7)(x+7)-(x-4)²=x²-49-x²+8x-16=8x-65
1) ( A + 1)^2 + ( A - 1 )^2 = A^2 + 2A + 1 + A^2 - 2A + 1 = 2A^2 + 2 = 2 *( A^2 + 1)
2) 3A^2 + 3 = 3 * ( A^2 + 1 )
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[ 2 * ( A^2 + 1 ) ] / [ 3 * ( A^2 + 1 ) ] = 2/3
Ответ 2/3