What is the value of x in the following equation: 2x+4x=15 ?

Whats the name of the vertical axis

Nick has box brads. he uses 4 brads for the first project. nick let’s b represent the original number of brads and finds that for the second project, the number of brads he uses is 8 more than half the difference of b and 4. write an expression to represent the number of brads he uses for the second project.

Which expression gives you the distance between the points (5,1)and(9,-6)