P-3(p-2(r--4(9-1,5(r-+(p+2p-3(p+9))

p-3(p-2(r-s))-(-p-4(9-1.5(r-s)))+(p+2p-3(p+9))=p-3(pr-ps-2r+2s)-(-p-4(9r-9s-1.5r+1.5s))+(p²+9p+2p²+18p-3p-27)=p²n-p²s-2np+2sp-3pn+3ps+6n-6s-(9rp+9sp+1.5rp-1.5sp-36r+36s+6r-6s)=p²n-p²s-2np+2sp-3pn+ps+6n-6s+9rp-9sp-1.5rp+1.5sp+36r-36s-6r+6s=p²n-p²s-5pn-2.5sp+6n-36s+9.5rp+30r