Please help .

Find the value of the variable and the length of each secant segment.

Use stokes' theorem to evaluate c f · dr where c is oriented counterclockwise as viewed from above. f(x, y, z) = xyi + 5zj + 7yk, c is the curve of intersection of the plane x + z = 8 and the cylinder x2 + y2 = 81.

The seventh-grade students at charleston middle school are choosing one girl and one boy for student council. their choices for girls are michaela (m), candice (c), and raven (r), and for boys, neil (n), barney (b), and ted (t). the sample space for the combined selection is represented in the table. complete the table and the sentence beneath it.