+146 im taking an online class and i dont get how to expand the binomial (2x+5)^5 can someone explain how i would do this?
+23252 If you use combinations: (2x + 5) ^ 5:
5nCr5·(2x)^5·(5)^0 + 5nCr4·(2x)^4·(5)^1 + 5nCr3·(2x)^3·(5)^2 + 5nCr2·(2x)^2·(5)^3 + 5nCr1·(2x)^1·(5)^4 + 5nCr0·(2x)^0·(5)^5
= 1·32x^5·1 + 5·16x^4·5 + 10·8x^3·25 + 10·4x^2·125 + 5·2x·625 + 1·x^0·3125
= 160x^5 + 400x^4 + 2000x^3 + 5000x^2 + 6250x + 3125
+23252 If you use combinations: (2x + 5) ^ 5:
5nCr5·(2x)^5·(5)^0 + 5nCr4·(2x)^4·(5)^1 + 5nCr3·(2x)^3·(5)^2 + 5nCr2·(2x)^2·(5)^3 + 5nCr1·(2x)^1·(5)^4 + 5nCr0·(2x)^0·(5)^5
= 1·32x^5·1 + 5·16x^4·5 + 10·8x^3·25 + 10·4x^2·125 + 5·2x·625 + 1·x^0·3125
= 160x^5 + 400x^4 + 2000x^3 + 5000x^2 + 6250x + 3125
