Răspuns:
a)a•7=3•28; a=84:7; a=12
b)a•3,5=2•7; a=14:3,5; a=4
c)a•a=9•4; 2a=36; a=36:2; a=18
d)(2a)•0,9=0,6•21; 2a=12,6:0,9; a=11,34:2; a=5,67
