Question 46738
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Expand the binomial: (3-y)^3
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        The "solution" in the post by @consc198 has nothing in common with the truth.

        For correct solution, see my post below.


<pre>
As you are going to expand the binomial, you should know, as a prerequisite,
this expanding formula for binomials of degree 3


    {{{(a+b)^3}}} = {{{a^3}}} + {{{3a^2*b}}} + {{{3ab^2}}} + {{{b^3}}}. 


To get the required expanding, plug in here a = 3,  b = -y.  You will get


    {{{(3-y)^3}}} = {{{3^3}}} - {{{3*3^2*y}}} + {{{3*3*y^2}}} - {{{y^3}}} = {{{27}}} - {{{27y}}} + {{{9y^2}}} - {{{y^3}}}.     <U>ANSWER</U>
</pre>

Solved correctly.