42:6•х=63. (68-12):х=2.
7x=63
x=8
48:x=2
42:6*x=63 7x=63 x=9
(68-12)•x=2 54:x=2 x=54:2 x=27
7*x=63 x=63:7=9 56:x=2 x=56:2=28