I need help with the steps to get the ans. please

A wall is made from an inhomogeneous (nonuniform) material for which the thermal conductivity varies through the thickness according to k=ax+b, where a and b are constants. The heat flux is known to be constant. Determine expressions for the temperature gradient and the temperature distribution when the surface at x=0 is at temperature T1. (Ans: T=T1+aqxlnax+bb )