250t/3 +6t/3=256t/6=256•(-4t/6) = 1024t/6
(a+b)²= a² +2ab + b²
(a-b)²= a² -2ab + b²
(a+b)(a-b) = a² - b²
(a+b)³ = a³ + 3a²b + 3ab² + b³
( a - b)³ = a³ - 3a²b + 3ab² - b³
a³ + b³ = (a+b)(a² -ab + b²)
a³ - b³ = (a -b)(a² +ab + b²)
42x^2y^6/63x^4y^6=2x^-2/3=2/3x^2