Answer:

Step-by-step explanation:
The equation for the monthly charge has the following format

In which y(x) is the cost in function of the number of kilowatt-hours used(x), a is the price of each killowatt hour and b is the fixed(base) charge.
Base charge of $17.32 per month.
This means that 
charge of 7.32 cents per kilowatt-hour
Our answer is in dollars. Each dollar is 100 cents. So 7.32 cents is 
Write an equation for the monthly charge y in terms of x, the number of kilowatt-hours used.


Step-by-step explanation:
Y=-4x+3
2x+3y=19
2x+3(-4x+3)=19
2x-12x+9=19
-10x=10
X=-1
y=-4*(-1)+3=4+3=7
x=-1 y=7
Answer:
It appears to be substitution
Step-by-step explanation:
I think you are talking about system of equations
Answer: 5 gallons
Step-by-step explanation: the gallons are in decimal points. 1/2 + 1/2 + 2 + 1 = 5. the .05 and 1/2 are the same thing. the .5 + .5 equals 1