Let G for Gina’s grade
J for Jessica's
H for Haley's
Given G + J + H =249 ...........(1)
G = J -52....................................(2)
H = J/2 +49 ........................(3)
Substituting values of (2) in (1)
G +G+52 +H =249 or
2G +H = 197.................................(4)
From (2) and (3)
2H –G = 150..................................(5)
Solving (4) and (5)
H= 497/5 = 99.4
And G = 48.8
Substituting the values of H and G in (1)
48.8 +J + 99.4 = 249
J = 100.8
J for Jessica's
H for Haley's
Given G + J + H =249 ...........(1)
G = J -52....................................(2)
H = J/2 +49 ........................(3)
Substituting values of (2) in (1)
G +G+52 +H =249 or
2G +H = 197.................................(4)
From (2) and (3)
2H –G = 150..................................(5)
Solving (4) and (5)
H= 497/5 = 99.4
And G = 48.8
Substituting the values of H and G in (1)
48.8 +J + 99.4 = 249
J = 100.8