Question

John has 15 more baseball cards than Michael. Together they have a total of 55 cards. How many cards does Michael have? Let M = the number of baseball cards Michael has.

Answer 1

M= J +15
M+J =55

Solve for J in the first equation
m= j +15
m- 15 = j

Substitute in second equation
m + (m-15) = 55
m + m-15=55
2m - 15 = 55
2m = 70
m=35