x will be the turner family, y will be the James family
using the givens we construct first this equation
[tex]25x + 15y = 1475 [/tex]
then this one
[tex]x + y = 75 [/tex]
multiply the second by 15 to get
[tex] 15x + 15y = 1125[/tex]
now subtract it from the first to get
[tex]10x = 350 \\ x = 35[/tex]
substitute to find that
[tex]35 + y = 75 \\ y = 40[/tex]
35 hours for Turner, 40 hours for James