Question 240446
{{{4y^4*y^2 = 4y^6}}}
{{{4y^4*y =4y^5}}}
{{{y^2*y^2=y^4}}}
{{{y^2*y=Y^3}}}

Add them all together gives

{{{4y^6+4y^5+y^4+y^3}}}

Remember that in general {{{y^a+y^b}}} does not equal {{{y^(a+b)}}}