Answer:
6x+9x+4-11=21x-7
15x-7=21x-7
15x-21x=0
x=0
n = 9
Step-by-step explanation:
3(n+7)=48
distribute
3n +21 = 48
subtract 21 from each side
3n = 48-21
3n = 27
divide by 3
3n/3 = 27/3