Asap with numbers 39,40,41,42 i need

Refer to interactive solution 17.45 to review a method by which this problem can be solved. the fundamental frequencies of two air columns are the same. column a is open at both ends, while column b is open at only one end. the length of column a is 0.504 m. what is the length of column b?

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

Given the sequence 7, 14, 28, 56, which expression shown would give the tenth term? a. 7^10 b. 7·2^10 c. 7·2^9