Answer:
Jackie sold 12 cars.
Step-by-step explanation:
If we call the number of cars Oscar sold O, and the number of cars Jackie sold J, we can say the following:
O = J + 6
As Oscar sold 6 cars more than Jackie.
Together, they sold 30 cars.
O + J = 30
Since we know that:
O = J + 6
... we can put this into our previous equation.
O + J = 30
(J + 6) + J = 30
J + J + 6 = 30
2 * J + 6 = 30
Subtract 6 from both sides:
2 * J = 24
Divide both sides by 2:
J = 24 / 2
J = 12
Jackie sold 12 cars.
