Answer:
1. n=2
2. y=22/5
3. x=1/30
4. y=9
5. n=3
Step-by-step explanation:
1. 12-2n=4n
-2n-4n= -12
-6n= -12
n= -12/-6
n=2
2. 5y-9=13
5y= 13+9
5y=22
y=22/5
3. 1/2x + 3=13
2x/2x + 3×2x=18×2x
1+3×2x=18×2x
1+6x=36x
-30x= -1
x= -1/-30 ----- Determine the sign
x=1/30
4. 2y+6=15+y
2y-y=15-6
y=15-6
y=9
5. 7n=15+2n
7n=2n=15
5n=15
n=3
