7! ----- 3! 4! { expand fac into series of multiplications } P(2,3,4,5,6,7) ----------------- P(2,3) * P(2,3,4) { merge multiplied products } P(2,3,4,5,6,7) ----------------- P(2,2,3,3,4) { cancel like terms across division boundary } P(/,/,/,5,6,7) ----------------- P(/,2,/,3,/) { multiply and divide remaining terms } 5 * 6 * 7 --------- 2 * 3 { result } 35