Răspuns :
daca 4 e solutir putem inlocui in ecuatie
16-4a+20=0
36=4a a=9
x^2-9x+20=0
delta=81-80=1
x1=10/2=5
x2=8/2=4
ma=radical din 20
16-4a+20=0
36=4a a=9
x^2-9x+20=0
delta=81-80=1
x1=10/2=5
x2=8/2=4
ma=radical din 20
4 este solutie ,deci verifica ecuatia data
[tex]4^2-a*4+20=0 \\ 16-4a+20=0\\ 36=4a \\ a=36:4\\ a=9[/tex]
Cum a =9=>
[tex] x^{2}-9x+20=0 \\ \Delta= 81-80=1 \\ x_1=4 \\ x_2=5[/tex]
Media geometrica a numerelor 4 si 5 este:
[tex]Mg(4,5)= \sqrt{4*5} = \sqrt{20} =2 \sqrt{5} [/tex]
[tex]4^2-a*4+20=0 \\ 16-4a+20=0\\ 36=4a \\ a=36:4\\ a=9[/tex]
Cum a =9=>
[tex] x^{2}-9x+20=0 \\ \Delta= 81-80=1 \\ x_1=4 \\ x_2=5[/tex]
Media geometrica a numerelor 4 si 5 este:
[tex]Mg(4,5)= \sqrt{4*5} = \sqrt{20} =2 \sqrt{5} [/tex]