Answer:
A. $2.84
Step-by-step explanation:
15 gallons
6*[4-(42-63)]=
6*[4-(-21)]=
6*[4+21]=
6*25=150.
6*[4-9÷3]=
6*[4-27]=
6*(-23)=-138.
6*[4-3]=
6*1=6.