please derive the equation for the given picture!!

Question \#5: Two-fluid U-tube Manometer. Using pressure balances on the fluids found in the figure below, derive the given equation explicitly. papb=(RR0)(AB+AaBAaC)g Let Am2 be the cross-sectional area of each of the large reservoirs and am2 be the cross-sectional area of each of the tubes forming the U. R0 is the manometer reading when pa=pb R is the actual manometer reading A is the density of the heavier fluid 8 is the density of the lighter fluid