Răspuns :
[tex]\it -3x^2+11x+20=0\\ \\ x=5 \Rightarrow -3\cdot5^2+11\cdot5+20=0 \Rightarrow -75+55+20=0 \Rightarrow 0=0 \Rightarrow \\ \\ \Rightarrow x=5\ este\ solu\c{\it t}ie,\ deci\ propozi\c{\it t}ia\ este\ adev\breve arat\breve a[/tex]
Adevărat!
Răspuns:
-3×5²+11×5+20=0
= -3×25+55+20=0
= -75+55+20=0
= -75+75=0
=> 0=0 (adevărat)