Răspunsuri

2014-02-13T11:16:35+02:00
A)  \frac{x+7}{x+8}* \frac{1}{x+7}= \frac{x+7}{(x+8)*(x+7)} = \frac{1}{x+8}
am rezolvat doar una. celelalte imi dau de cap...
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2014-02-13T12:08:14+02:00
a) \frac{x+7}{x+8} * \frac{1}{x+7} = \frac{1}{x+8}

b)(mx+my)/( x^{2}+3x ) * (x-3)/(x+y)= m(x-3)/( x^{2} +3x)

c)[(x^2 -xy)*(x^2+xy^2)]/[(x^2+xy)*xy]= [x(x-y)*y(x^2+xy) / [(x^2+xy)*xy] =[ xy*(x-y)*(x^2+xy)] / [(x^2+xy)*xy] => se reduc xy si x^2+xy si ramane rezultatul x-y

d)
[(a^2 - 4b^2) / (a^2-ab)]* [(a-b) / (a^2+2ab)]= [(a^2-4b^2) *(a-b) ] / [a(a-b)* a(a+2b)]

=> (a^2-4b^2)= (a+2b)(a-2b) din formula (a^2 - b^2)=(a+b)(a-b)
inlocuind in relatie se reduc (a+2b) si (a-b) si ramane rezultatul (a-2b)/a^2
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