You've not learned that all of the constraints have to come after the "given" statement? Where is "Find"?
Go read the help files about how to set up a solve block!
Or are you just dumping on this forum?
i have a question so only i want to find d.1 d.2.
all variables are a constant value.
so do I have to change d.a=0.1 not :=
If ALL of your used variables have to be constant (even q=100) and you only want to vary d1 and d2m then you are asking for the impossible. There is a linear relationship between d1 and d2 and to fulfill your equation at least one of the two must be negative. So they can't be both in the range from 0 to 0.3.