Card Collecting

Question

Andre, Laura, and Danielle each collect baseball cards.

 Andre has three more than double the number of cards that Danielle has.

 Laura has four fewer cards than Danielle.

 All together they have a total of 43 cards.

Use an equation to determine the number of cards that each person has in their collection. Show your work.

Answer 1

First, note that three equations is sufficient to determine the values of three variables. Let A, L, and D represent the number of baseball that each has.

1) A = 2D + 3

2) L = D - 4

3) A + D + L = 43

After studying the three formulas, you may notice that D appears on the right side of equations (1) and (2), so we may re-write equation (3) as:

(2D + 3) + D + (D - 4) = 43

4D -1 = 43

D = 11

Now, use that value of D with equation (1) and (2) to find the other values.

IMPORTANT: Be sure to check your answer by substitution the values of A, D, and L into the three equtions to verify that your answer work.

Answer 2

d represents the number of cards Danielle has

2d + 3 represents the number of cards Andre has

d - 4 represents the number of cards Laura has

d + 2d + 3 + d - 4 = 43

Can you solve for d and answer?