Question 1046202
let m = Marks present age
let d = diane's
:
Write an equation for each statement, simplify as much as possible
:
Three years ago, Mark was twice as old as Diane.
m - 3 = 2(d - 3)
m - 3 = 2d - 6
m = 2d - 6 + 3
m = 2d - 3
:
 Four years from now, twice Mark's age will be three less than three times Diane's age.
2(m+4) = 3(d+ 4) - 3
2m + 8 = 3d + 12 - 3
2m = 3d + 9 - 8
2m = 3d + 1
replace m with (2d - 3) from the first statement
2(2d-3) = 3d + 1
4d - 6 = 3d + 1
4d - 3d = 6 + 1
 d = 7 yrs is Diane's present age
then
 m = 2(7) - 3
m = 11 yrs is Marks age
:
;
You can check this for yourself in both statements