Finding the Gigabyte Offset in Plans A and B

A telecommunications company offers two types of plans for its customers. The monthly cost of Plan A can be modeled by the equation:

$$C_A(x) = 20 + 5x$$

where $$x$$ is the number of gigabytes used. Plan B's cost is represented by:

$$C_B(x) = 15 + 4x$$

Customers want to find out after how many gigabytes the costs of both plans will be equal. To solve this, set the two equations equal to each other and solve for $$x$$.