Question

What is (2+y)³ written out?

Answer 1

${ \left( 2+y \right) }^{ 3 }\\ \\ =\left( 2+y \right) \left( 2+y \right) \left( 2+y \right) \\ \\ =\left( 2+y \right) \left( 4+4y+{ y }^{ 2 } \right)$

$\\ \\ =2\left( 4+4y+{ y }^{ 2 } \right) +y\left( 4+4y+{ y }^{ 2 } \right) \\ \\ =8+8y+2{ y }^{ 2 }+4y+4{ y }^{ 2 }+{ y }^{ 3 }\\ \\ ={ y }^{ 3 }+6{ y }^{ 2 }+12y+8$