Express the area of a rectangle with a length of 4x^3 and a width of 5 as a monomial

Proceed as in example 3 in section 6.1 to rewrite the given expression using a single power series whose general term involves xk. ∞ n(n − 1)cnxn − 2 n = 2 − 4 ∞ ncnxn n = 1 + ∞ cnxn n = 0

What is the value of x when x + 7 = 21?

Why is studying fractions important