Answer:
3 : 7 : 5
Step-by-step explanation:
Given
12 : 28 : 20 ← divide each part by 4 ( the LCM of 12, 28, 20 )
= 3 : 7 : 5
Binomial theory : ( a - b ) ^3 = a^3 - 3a^2b + 3ab^2 - b^3 ;
Then, ( 2y - 3x ) ^3 = 8y^3 - 36y^2x + 54yx^2 - 27x^3
A cylinder...
Vcylinder=hπr^2
Vcone=(hπr^2)/3
3*Vcone=Vcylinder