Sagot :
9m-28=2m
9m-28-2m=2m-2m
(9m-2m)-28=0
7m-28=0
7m-28+28=0+28
7m=28
(7m)/7 = 28/7
m=4
9m-28-2m=2m-2m
(9m-2m)-28=0
7m-28=0
7m-28+28=0+28
7m=28
(7m)/7 = 28/7
m=4
Subtract 2m on both sides, which leaves you with 7m=-28, divde -28 with 7 and equals to -4
-4=M
-4=M