y'=3[(3x+5)^2]*3*[(5x+4)^5]+[(3x+5)^3]*5*[(5x+4)^4]*5
=(3x+5)^2(5x+4)^4[9(5x+4)+25(3x+5)]
=(120x+161)(3x+5)^2(5x+4)^4