So,
We can re-write these statements in mathematical form.
Let h represent Holly and j represent Julia.
First equation:

Second equation:

This is our System of Simultaneous Linear Equations.
I'll solve.
Substitute

Collect Like Terms

Subtract 35 from both sides

Multiply both sides by

j = 48
Substitute 48 for j in the first equation
h + 48 = 107
Subtract 48 from both sides
h = 59
Check
59 + 48 = 107
107 = 107 This checks.
59 = 35 +

59 = 35 + 24
59 = 59 This also checks.
Holly scored 59 points and Julia scored 48 points.