How can I add conditions to a system of equations?

regarding this code, i want to add the conditions that the variables takes values between 1 and 9, so 1<q,w,e,r,t,y,u,i,o>9. thank you

syms q w e r t y u i o

eqn1= (w*r)/o==6

eqn2=(t-u)*q==8

eqn3=(1+y)/w==1

eqn4=((q*e)-0)/t==3

sol = solve([eqn1, eqn2, eqn3,eqn3], [q,w,e,r,t,y,u,i,o]);

qsol=sol.q

wsol=sol.w

esol=sol.e

rsol=sol.r

tsol=sol.t

ysol=sol.y

usol=sol.u

isol=sol.i

osol=sol.o

Answer 1

[Star Strider]

Use the assume function —

syms q w e r t y u i o real
assume([q w e r t y u i o]>=1 & [q w e r t y u i o]<=9)
eqn1= (w*r)/o==6

eqn1 = 

eqn2=(t-u)*q==8

eqn2 = 

eqn3=(1+y)/w==1

eqn3 = 

eqn4=((q*e)-0)/t==3

eqn4 = 

sol = solve([eqn1, eqn2, eqn3,eqn3], [q,w,e,r,t,y,u,i,o], 'ReturnConditions',1);
parms = sol.parameters

parms = 

condx = sol.conditions

condx = 

qsol=sol.q

qsol = 

wsol=sol.w

wsol = 

esol=sol.e

esol = 

rsol=sol.r

rsol = 

tsol=sol.t

tsol = 

z

ysol=sol.y

ysol = 

usol=sol.u

usol = 

isol=sol.i

isol = 

osol=sol.o

osol = 

That seems to work.

Experiment to get the desired results.

.