7. (2 +y)= c. 8. y(r+1) - c. 9. -- c 10. y(+c) +2-0. 11. -4ar.

i used homogeneous method..

solution of 7th

here is the solution... you can do other by similar method..

you first find Dy/dx and from this equation and given equation remove c. which gives you differential equation. and then in this DE replace Dy/dx by - dx/dy, which gives DE of orth...