Question

Fie functia f:R-R f(×)=×+3 si g:R-R g(×)=2×-1 sa se determine solutia reala a ecuatiei 2f(×)+3g(×)=-5

Answer 1

[tex]f(x)=x+3\\ g(x)=2x-1\\ 2f(x)+3g(x)=-5\ \textless \ =\ \textgreater \ 2*x+3+3*2x-1=-5(am~inlocuit)\\ 2x+3+6x-1=-5\\ 8x=-3+1-5\\ 8x=-2-5\\ 8x=-7\\\\ x= \frac{-7}{8} \\\\ Proba:-14+24-42-8=-40\\ 10-50=-40\\ -40=-40[/tex]

Answer 2

f,g:R-> R, f(x)=x+3, g(x)=2x-1
2f(x)+3g(x)=-5
2(x+3)+3(2x-1)=-5
2x+6+6x-3=-5
8x+3=-5
8x=-8
x=-1∈R
S:x=-1