To expand the binomial (3−x)6, we can use the binomial theorem, which states that for any real numbers a and b and a non-negative integer n, the expansion of (a+b)n is given by:
(a+b)n=∑k=0n(kn)an−kbk
where (kn) represents the binomial coefficient, which is the number of ways to choose k elements from a set of n elements and is defined as:
(kn)=k!(n−k)!n!
In our case, a=3 and b=−x, and n=6. Let's plug these values into the formula to expand (3−x)6:
(3−x)6=(06)36(−x)0+(16)35(−x)1+(26)34(−x)2+(36)33(−x)3+(46)32(−x)4+(56)31(−x)5+(66)30(−x)6
Now, let's calculate each term:
(06)36(−x)0=1⋅36⋅1=729
(16)35(−x)1=6⋅35⋅(−x)=−1458x
(26)34(−x)2=15⋅34⋅x2=405x2
(36)33(−x)3=20⋅33⋅(−x)3=−540x3
(46)32(−x)4=15⋅32⋅x4=405x4
(56)31(−x)5=6⋅31⋅(−x)5=−162x5
(66)3
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