Louie has 20 more than half as many baseball cards as Gerardo does. Together they have at least 350 cards.

In the question it is given that Louie has 20 more than half as many baseball cards as Gerardo does. So,

Let us assume that the number of baseball cards Gerardo has = X

Number of baseball cards that Louie has = 20 + X/2

Also the total number of baseball cards Louie and Gerardo has together is 350.

Then,

X + X/2 + 20 = 350

X + X/2 = 350 - 20

X + X/2 = 330

3X/2 = 330

3X = 330 * 2

3X = 660

X = 660/3

= 220

Number of baseball cards Gerardo has = 220

Number of cards Louie has = 130.