Answer:
When multiplying, add the exponents, (example) remember if there is "7b" the exponent is one.
Multiply b^2 * b^3 = b^5 (add the exponent 2 + 3 = 5)
Multiply 7b * b^3 = 7b^4 (the exponent of 7b is one, add 1 + 3 for the exponent to become 4)
Multiply 4 * b^3 = 4b^3 (4 doesn't have a variable, the exponent will be 3)
b^2 * b*2 = b^4 (add exponents)
7b * b^2 = 7b^3 (add the exponents 1 + 2)
4 * b^2 = 4b^2
b^2 + 7b + 4
b^3 b^5 + 7b^4 + 4b^3
+
b^2 b^4 + 7b^3 + 4b^2
b^5 + 7b^4 + 4b^3 + b^4 + 7b^3 + 4b^2

b^5 + 8b^4 + 11b^3 + 4b^2