[tex3]\{bx+ay=c\\ cx+az=b\\ cy+bz=a[/tex3]
Sendo, [tex3]a\neq 0,\ b\neq0,\ c\neq 0[/tex3] .
Determine o valor de [tex3]x[/tex3] :
(A) [tex3]\frac{a^2+b^2+c^2}{2bc}[/tex3]
(B) [tex3]\frac{b^2+c^2-a^2}{2bc}[/tex3]
(C) [tex3]\frac{b^2-c^2-a^2}{2bc}[/tex3]
(D) [tex3]\frac{-a^2-b^2-c^2}{2bc}[/tex3]
(E) [tex3]\frac{a^2+b^2-c^2}{2bc}[/tex3]
Resposta
B