Răspuns:
Explicație pas cu pas:
a=(2/3+5/8)*(12/31)= (16/24+15/24)*(12/31)=(31/24)*(12/31) =12/24=1/2
b=(3/√2)*(5√2-(3/2)*2√2)= (3/√2):(5√2-3√2)=(3/√2):2√2= 3/4
N=√(2*1/2+4*3/4)/2=√(1+3)/2=√4/2=2/2=1 ∈N
cam greu...