There are two equations to be solved here. The first one we assign variables to the home runs Peter hits, P, and Alice hits, A. P=2*(A-6) The second equation is the sum of both players home runs.P + A = 18Solving for P yieldsP=18-A We substitute the solution for P into the first equation and solve for A.(18-A) = 2*(A-6)18 - A = 2A - 123A = 30A = 10 Now that A is known, we can plug it into either equations for P to find how many home runs Peter hitsP=18 - (10) = 8orP=2((10)-4) = 8