Question

aflati x stiind ca 5 , 2x+5 , x^2+9 sunt 3 termeni consecutivi ai unei progresii aritmetice.
a=5
b=2x+5
c=x^2+9

Answer 1

mult succes incontinuare

Answer 2

a = 5  ; b = 2x+5 ; c = x²+9

r = b-a => r = 2x+5-5 = 2x

r = c-b => r = x²+9-2x-5 = x²-2x+4

x²-2x+4 = 2x => x²-4x+4 = 0 <=> (x-2)² = 0 => x-2 = 0 => x =2

a = 5 ; b = 9 ; c = 13 ; r = 4