answer
5
set up equations
daren is 3 years older than tom
D = 3 + T
3 years ago leah will be 14 less than 3 times darren's age
L - 3 = 3(D - 3) - 14
L - 3 = 3D - 9 - 14
L = 3D - 9 - 14 + 3
L = 3D - 20
5 years ago, leah was 2 years less than 2 times tom
L - 5 = 2(T - 5) - 2
L - 5 = 2T - 10 -2
L = 2T - 10 - 2 + 5
L = 2T - 7
find leah's current age
set L = 3D - 20 and L = 2T - 7 equal to each other
3D - 20 = 2T - 7
plug 3 + T into D using the equation D = 3 + T
3D - 20 = 2T - 7
3(3 + T) - 20 = 2T - 7
9 + 3T - 20 = 2T - 7
T = - 7 - 9 + 20
T = 4
plug T back into L = 2T - 7 to find leah's current age
L = 2T - 7
L = 2 * 4 - 7
L = 8 - 7
L = 1
leah's age 4 years from now
add 4 to leah's current age
1 + 4 = 5