8a^3 + c^3= ???

a. (2a+c)(2a+c)(2a+c)


b. (2a-c)(4a^2+2ac+c^2)


c.(2a x c)(4a^2+4ac+c^2)


d.(2a+c)(4a^2 x 2ac+c^2)





work will be apprciated

8a^3 + c^3= ???
hey
Reply:x³ + y³ = (x + y)(x² - xy + y²)


x³ = 8a³


y³ = c³


so x= 2a and y = c





(2a + c)[(2a)² - 2a(c) + c²]


(2a + c)(4a² - 2ac + c²)
Reply:Its none of them!


Theres not really a lot of work to show


Sum of 2 cubes


x^3 + y^3 = (x + y)(x² - xy + y²)


You will see this is true if you expand the brackets on the right hand side.


now you have x = 2a and y = c


((2a) + (c))( (2a)² - (2a)(c) + (c)²)


= (2a+c)(4a² - 2ac+c²)





B would be the solution to 8a^3 - c^3
Reply:8a^3 + c^3


= (2a + c)(4a^2 - 2ac + c^3)


(none of them)