Explicație pas cu pas:
a)E(x)=x²+2x+1+2(x²-1)+x²-2x+1=>
E(x)=2x²+2+2x²-2 =>
E(x)=4x²=>E(x)=(2x)²-p.p (A)
b)p=E(V1)+E(V2)+...+E(V10) =>
p=4*1+4*2+4*3+....+4*10=>
p=4(1+2+3+....+10)=>
p=4*10*11/2=>
p=2*10*11=>p=22*10=>p=220
E(x) = (x+1)^2 + 2 (x+1)(x-1) + (x-1)^2 = ((x+1) + (x-1))^2 = 4x^2
E(x)=4x^2 = (2x)^2 este patrat perfect pentru orice x
b) E(rad(1)) = 4
E(rad(2)) = 4 * 2 = 8
E(rad(3)) = 4 * 3 = 12
E(rad(10)) = 4 * 10 = 40
p = 4 + 4*2 + 4*3 + ... + 4*10 = 4 (1+2+3+...+10)
p = 4 * 11 * 10 / 2 = 220
p = 220
