Here we have an algebraic problem. We will find that the cost of the gas is R$16.26
Here we know that a car can travel 500km with 40L of gas.
Then we want to know how much costs to travel 36km (18 km two times), if each L of gas costs R$ 5,30.
First, we need to find how much the car can travel with 1L of gas.
To see this, we take the quotient between the distance we know it can travel with 40L of gas, we get:
500km/40L = 12.5 km/L
Now we know that the car travels 12.5 km per liter of gas.
Now let's define a variable X, which is the amount of gas that the car needs to travel 36km, we can write:
(12.5km/L)*X = 36km
Now we solve this for X:
X = (36km)/(12.5km/L) = 2.88 L
And we know that each liter costs R$ 5,30, then the cost of 2.88L is:
2.88*R$ 5,30 = R$16.26
She spends R$16.26 on gas.
If you want to learn more, you can read:
brainly.com/question/24519906