Question

Althea has 100 trading cards and Marlon has 20. Every day Althea gives Marlon one card. Use the equations "c=100-d" and "c=20+d" to model this situation. Solve the system by substitution. Explain what the solution means in this situation.

Answer 1

Explanation:

c=100-d {Equation 1}

c=20+d {Equation 2}

{Equation 1 + Equation 2}

2c=120 (-d+d= 0)So d is eliminated

c=120/2

c=60

Althea =

60=100-d(substitute c for 60 )

d=100-60

d=40

Check your answer by substituting both c and d

60=100-40(substituting using equation 1)

So 60=60

Answer is correct!

C is the Althea's and Marlon's letter

D is the amount of cards that Althea gives and Marlon receives..