Answer :
3m-7n=p, add 7n to both sides, 3m= 7n+p, divide everything by 3, m= 7/3n+1/3p
3m-7n=p
add 7n to both sides you get 3m=p+7n
then divide 3 from both sides and get m=p+7n over 3
add 7n to both sides you get 3m=p+7n
then divide 3 from both sides and get m=p+7n over 3