Answer:
x=1
Step-by-step explanation:
3(4x+1)=15
12x+3=15
12x=15-3
12x=12
x=12/12
21 With glasses
32/20=1.6
1.6•7=11.2 Without Glasses
1.6•13=20.8 With Glasses
20.8 rounded to nearest whole number=21