You can expand as follows:
Expand the following:
(sqrt(x)+5)^3
(5+sqrt(x))^3 = sum_(k=0)^3 binomial(3, k) (sqrt(x))^(3-k) 5^k = binomial(3, 0) (sqrt(x))^3 5^0+binomial(3, 1) (sqrt(x))^2 5^1+binomial(3, 2) (sqrt(x))^1 5^2+binomial(3, 3) (sqrt(x))^0 5^3:
binomial(3, 0) x^(3/2)+5 binomial(3, 1) x+25 binomial(3, 2) sqrt(x)+125 binomial(3, 3)
binomial(3, 0) = 1, binomial(3, 1) = 3, binomial(3, 2) = 3 and binomial(3, 3) = 1:
5^3+5^2×3 sqrt(x)+5×3 (sqrt(x))^2+(sqrt(x))^3
5^2 = 25:
5^3+25×3 sqrt(x)+5×3 (sqrt(x))^2+(sqrt(x))^3
Cancel exponents. (sqrt(x))^2 = x:
5^3+25×3 sqrt(x)+5×3 x+(sqrt(x))^3
5^3 = 5×5^2:
5×5^2+25×3 sqrt(x)+5×3 x+(sqrt(x))^3
5^2 = 25:
5×25+25×3 sqrt(x)+5×3 x+(sqrt(x))^3
5×25 = 125:
125+25×3 sqrt(x)+5×3 x+(sqrt(x))^3
25×3 = 75:
125+75 sqrt(x)+5×3 x+(sqrt(x))^3
5×3 = 15:
125+75 sqrt(x)+15 x+(sqrt(x))^3
Multiply exponents. (sqrt(x))^3 = x^(3/2):
Answer: | 125+75 sqrt(x)+15 x+x^(3/2)