Question

dacă 1/(x+1)+1/(y+1)+1/(z+1)+1/(t+1)=3, calculati x(x+1)+y/(y+1)+z/(z+1)+t/(t+1)

Answer 1

[tex]\frac{1}{x+1}+\frac{1}{y+1}+\frac{1}{z+1}+\frac{1}{t+1}=3\\ \frac{x}{x+1}+\frac{y}{y+1}+\frac{z}{z+1}+\frac{t}{t+1}=S\\ Adunam\ relatiile\\ \frac{x+1}{x+1}+\frac{y+1}{y+1}+\frac{z+1}{z+1}+\frac{t+1}{t+1}=3+S\\ 1+1+1+1=3+S\\ 4=3+S\\ S=1 [/tex]