(2y/(y+b)+(b-y)/y)/((b²+y²)/(b+y))=((2y²+b²-y²)/(y*(y+b))/((b²+y²)/(b+y)=
=((b²+y²)/(y*(b+y))/((b²+y²)/(b+y))=1/y.
18х * х^2 = 18*х^3 = 18х^3
Решение задания смотри на фотографии
<span>(b+19)</span>²=b²+38b+361
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