Răspuns:
A. x+y+y+z=(x+y)(y+z) =1,5×7,4=11,1
b.11,1 rotunjit=11,0
C. 3(x+y)+3(y+z)=3×1,5+3×7,4=4,5+22, 2+26,7
26,7+26,7=52,14