Find the value of a if y=a/7x + c is parallel to y = 2x - 4

The mean of a set of data is -3.82 and its standard deviation is 2.31. find the z score for a value of 3.99.

Aright triangle has an area of 18 square inches. b: if the triangle is not an isosceles triangle, what are all the possible lengths of the legs, if the lengths are whole numbers. answer !

The ksp expression for the system pbcl2(s) pb+2(aq) + 2 cl-(aq) is: [pbc12][pb+2][2cl-] [pb+2][cl-]2 [pb+2][2cl-]2 [pbcl2][pb+2][cl-]2 [pb+2][2cl-]2[pbcl2]