what is the pressure at apoint 10 m below the free surface in fluid that has with solution variable density in kg/m3 given by p=45+ah, in which a=12 kg/m4 and h is the distance measured from the free surface with solution

Answer 1

From your given equation (using p as rho), the density at that depth is:
p = 45 kg/m³ + (12 kg/m^4)(10 m)
p = 165 kg/m³

Pressure = pgh
= (165 kg/m³)(9.8 m/s ² )(10 m)
= 16170 kg/m-s²
= 16170 Pa
= 16.17 kPa