What is the reciprocal of 1 and a does anyone know 21-23

Matt and brian were solving a system of equations. they both noticed that the two lines had the same slope. brian said that because each line in the system had the same slope, the two lines had to be parallel, which meant the solution to the system was "no solution" matt disagreed, and said they should also look at the y-intercepts before determining how many solutions there were. who is correct?

Consider the integral: 4 0 16 − y2 − 16 − y2 4 1 x2 + y2 dz dx dy . (a) describe w. use the standard view of the x, y, and z axes. front half of a cone with a rounded top. full cone with a flat top. right half of a cone with a flat top. front half of a cone with a flat top. right half of a cone with a rounded top.

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