В)
(х-1+х+2-х-1)/х-у=х/х-у
г)
((а-4)(а+2)-а(а-2))/а(а+2)=(а^2+2a-4a-8-a^2+2a)/a(a+2)=-8/a(a+2)
Возводи в квадрат,
x<5 и x>1
(4x-7)/16(x-√2)(x+√2)>0
x=1,75 x=√2 x=-√2
_ + _ +
--------------(-√2)---------------(√2)---------------(1,75)---------------
x∈(-√2;√2) U (1,75;∞)
7ab-63b=7b(a-9)
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