Question

Exercitiul 6 va rog poza este mai jos

Answer 1

 

$\displaystyle\bf\\\frac{-b}{2a}=2\\\\f(2)=12\\\\-b=4a\\2^2\cdot a+2b+a=12\\\\4a+b=0\\4a+2b+a=12\\\\4a+b=0~~~|~\times(-2)\\5a+2b=12\\\\-8a-2b=0\\5a+2b=12\\------- adunam\\-3a~~/~= 12\\\\a=\frac{12}{-3}\\\\\boxed{\bf~a=-4}\\\\4\times(-4)= -b\\-16 = -b\\\boxed{\bf~b=16}\\\\\boxed{\bf~f(x)=-4x^2+16x-4=0}$