Question

Berapa hasil dari ((2r - 7s) - (r - 2s)) (r-2s)

Answer 1

[(2r - 7s)-(r - 2s)](r - 2s)
= (2r - 7s - r + 2s)(r - 2s)
 = (r - 5s)(r - 2s)
= r² - 2rs - 5rs + 10s²
= r² - 7rs + 10s²