Use the Binomial Theorem to expand (x+7)4 and express the result in simplified form?

1 Answer
May 17, 2018

2401+1372x+294x2+28x3+x4

Explanation:

Using binomial theorem we can express (a+bx)c as an expanded set of x terms:
(a+bx)c=cn=0c!n!(cn)!acn(bx)n

Here, we have (7+x)4

So, to expand we do:
4!0!(40)!740x0+4!1!(41)!741x1+4!2!(42)!742x2+4!3!(43)!743x3+4!4!(44)!744x4

4!0!(40)!74x0+4!1!(41)!73x1+4!2!(42)!72x2+4!3!(43)!7x3+4!4!(44)!70x4

4!0!4!74+4!1!3!73x+4!2!2!72x2+4!3!1!7x3+4!4!0!x4

74+4(7)3x+24472x2+4(7)x3+x4

2401+1372x+294x2+28x3+x4