The equation e = 6 tells you for each box, e, there are 6 eggs. If she bought 4 boxes, you would be multiplying the number of boxes, 4, by e. That means: 4 x e
Now you need to set 4 x e equal to the total number of eggs she has now. Since you know e = 6 eggs, plug in 6 into 4 x e! 4 x e = ? 4 x 6 = 24