Am nevoie de ajutor

a)a= 6V5 -12= 6×2,23-12= 1,38
b= 4×3,31-12= 13,24-12=1,24
a >b
b) x= 7-4×1,71= 7-6,84= 0,16
y= 7-5×1,44= 7-7,2= -0,2
x >y