Find the sum of an arithmetic series with the given number of terms a1 and an 27. 10 terms, a1 = 4, a 10 = 31

28. 15 terms, a1 = 17, a15 =129

Side xy of triangle xyz is extended to point w, creating a linear pair with ∠wyz and ∠xyz. measure of an exterior angle what is the value of x? 64 80 100 180