Răspunsuri

2014-05-26T20:50:16+03:00
A) a= (√5 + √3)^2 = 5 + 2√15 + 3 = 8 + 2√15 
b= (√5-√3)^2 = 5 - 2√15 + 3  = 8 - 2√15 
Media aritmetica = 8 - 2√15 + 8 + 2√15 / 2 = 16/ 2 = 8 

b) AxB - 9xC = (3x-2)*(3x+2) + 9*(x-3)
= 9x^2 + 6x - 6x - 4 + 9x - 27 = 9x^2 + 9x - 31 
1 5 1