Respuesta :

  I believe your equation (- 5r2s)(rs2) should have been written (-5r².s)(r.s²)
If so, remember that aⁿ x . aˣ = a⁽ⁿ⁺ˣ⁾

Multiply each term of te second parenthesis by each term of the 1st parenthesis:


= - 5. r²⁺¹.s²⁺¹. = -5.r³. s³