Explanation:
8, 12(3-x)=48
36-12x=48
-12x=48-36
-12x=12 both side divideos by -12
-12x/-12=12/-12
x= 1
9, x/7=4.5 cris cross
x=31.5
10,5(x-3)=45
5x-15=45
5x=45+15
5x=60 both side divided by 5
5x/5=60/5
x=12
11,-3(x-3)=45
-3x+3=45
-3x=45-3
-3x=42 both side divided by -3
-3x/-3=42/-3
x=14
12,14y-8=13
14y=13+8
14y=21 both side divided by 14
14y/14=21/14
y=1.5
13,3m=5m-8/5
3m-5m=-8/5
-2m=-8/5 cris cross
-10m=-8 both side divided by -10
-10m/-10=-8/-10
x=0.8