differential equation programming boundary condition

In order to compute the oslution of the differential system with bvp5c:

f''(t) = 3*f(t)*g(t) + 5 g''(t) = 4*g(t)*f(t) + 7 with initial conditions: f(0) = 1.5, g'(0) = 0 and boundary constraints defined at tf = 1: g(1) = 3, f'(1) =q* f(1) , I used somme code that work with the boundary condition : f'(1) =f(1), but I want to solve my problem with the condition: f'(1) =q* f(1) with q a natura number , my question is can we replace this condition by f'(1) =1.5*q*exp(q) beacuse it easy to progamme this condition (because the solution of the differential equation f'(x) =q* f(x) has the forme f(x)=C*exp(qx) and I know tha C in our case equal f(0)=1.5)