Examples
(x-7)3(x−7)3
Step 1
Use the binomial expansion theorem to find each term. The binomial theorem states (a+b)n=n∑k=0nCk⋅(an-kbk)(a+b)n=n∑k=0nCk⋅(an−kbk).
3∑k=03!(3-k)!k!⋅(x)3-k⋅(-7)k3∑k=03!(3−k)!k!⋅(x)3−k⋅(−7)k
Step 2
Expand the summation.
3!(3-0)!0!(x)3-0⋅(-7)0+3!(3-1)!1!(x)3-1⋅(-7)1+3!(3-2)!2!(x)3-2⋅(-7)2+3!(3-3)!3!(x)3-3⋅(-7)33!(3−0)!0!(x)3−0⋅(−7)0+3!(3−1)!1!(x)3−1⋅(−7)1+3!(3−2)!2!(x)3−2⋅(−7)2+3!(3−3)!3!(x)3−3⋅(−7)3
Step 3
Simplify the exponents for each term of the expansion.
1⋅(x)3⋅(-7)0+3⋅(x)2⋅(-7)1+3⋅(x)1⋅(-7)2+1⋅(x)0⋅(-7)31⋅(x)3⋅(−7)0+3⋅(x)2⋅(−7)1+3⋅(x)1⋅(−7)2+1⋅(x)0⋅(−7)3
Step 4
Step 4.1
Multiply (x)3(x)3 by 11.
(x)3⋅(-7)0+3⋅(x)2⋅(-7)1+3⋅(x)1⋅(-7)2+1⋅(x)0⋅(-7)3(x)3⋅(−7)0+3⋅(x)2⋅(−7)1+3⋅(x)1⋅(−7)2+1⋅(x)0⋅(−7)3
Step 4.2
Anything raised to 00 is 11.
x3⋅1+3⋅(x)2⋅(-7)1+3⋅(x)1⋅(-7)2+1⋅(x)0⋅(-7)3x3⋅1+3⋅(x)2⋅(−7)1+3⋅(x)1⋅(−7)2+1⋅(x)0⋅(−7)3
Step 4.3
Multiply x3x3 by 11.
x3+3⋅(x)2⋅(-7)1+3⋅(x)1⋅(-7)2+1⋅(x)0⋅(-7)3x3+3⋅(x)2⋅(−7)1+3⋅(x)1⋅(−7)2+1⋅(x)0⋅(−7)3
Step 4.4
Evaluate the exponent.
x3+3x2⋅-7+3⋅(x)1⋅(-7)2+1⋅(x)0⋅(-7)3x3+3x2⋅−7+3⋅(x)1⋅(−7)2+1⋅(x)0⋅(−7)3
Step 4.5
Multiply -7 by 3.
x3-21x2+3⋅(x)1⋅(-7)2+1⋅(x)0⋅(-7)3
Step 4.6
Simplify.
x3-21x2+3⋅x⋅(-7)2+1⋅(x)0⋅(-7)3
Step 4.7
Raise -7 to the power of 2.
x3-21x2+3x⋅49+1⋅(x)0⋅(-7)3
Step 4.8
Multiply 49 by 3.
x3-21x2+147x+1⋅(x)0⋅(-7)3
Step 4.9
Multiply (x)0 by 1.
x3-21x2+147x+(x)0⋅(-7)3
Step 4.10
Anything raised to 0 is 1.
x3-21x2+147x+1⋅(-7)3
Step 4.11
Multiply (-7)3 by 1.
x3-21x2+147x+(-7)3
Step 4.12
Raise -7 to the power of 3.
x3-21x2+147x-343
x3-21x2+147x-343