(X-30)[1500+400(40-X)]=17500 (x-30)(17500-400x)=17500 (x-30)(175-4x)=175 175x-4x^2-5250+120x=175 4x^2-295x+5425=0 (4x-155)(x-35)=0 x1=155/4 x2=35
