punctul a)
c(5c-1) / (5c-1)(5c-1) + 4 / (1-5c)(1+5c) = c / (5c-1) - 4 / (5c-1)(5c+1) = (5c^{2} + c - 4) / (5c-1)(5c+1)
1 - 3 / (5c-1) = (5c-4) / (5c-1)
(5c-4)(c+1) / (5c-4)(5c+1) = (c+1) / (5c+1)
si daca mai scadem c / (5c+1) obtinem 1 / (5c+1)
punctul b)
prima parte:
-(4a-3)^2/(4a-3)(4a+3) + 1/[a(4a+3)]
-a(4a-3)+1 / a*(4a+3)
3 - 7a/(a-1) = -(3+4a)/(a-1)
facand inmultirea avem:
(-4a^2+3a+1)/a * -1/(a-1) => (a-1)(4a+1)/a*(a-1) = (4a+1) / a
daca scadem 1/a obtinem 4
