The perpendicular bisector of line segment $\overline{ab}$ is the line that passes through the midpoint of $\overline{ab}$ and is perpendicular to $\overline{ab}$. What is an equation for the perpendicular bisector of the line segment joining $(1,2)$ and $(-5,12)$? write your equation in point-slope form, standard form, or slope-intercept form.

Of four agents alpha, beta, gamma anddelta, three have to be sent together on amission. if alpha and beta cannot gotogether, beta and gamma cannot go togetherand gamma and delta cannot go together, then which of the following holds? 1. any three agents can be sent.2. alpha, delta and any one out of beta andv gamma can be sent.3. beta, gamma and any one out of alphaand delta can be sent.4. the mission is impossible.

Give an example of the type and scale of economic activity for a traditional economy.

Summarize the work of famous environmental scientists of the past.