If there is a parallelogram with one pair of opposite sides that are congruent and another pair that is parallel, how do i prove it is a parallelogram?

Which of the expressions (on the photo document i inserted) together represent all solutions to the following equation? 8cos(12x)+4=-4 *the answer should be in degrees.* > i would like for someone to explain the process to find the solutions for this.

Find solution of the linear equation y = 2/3x + 1/3

The students in a class were asked how many siblings they have. the data obtained is represented in the dot plot. the number of students who have no siblings is . the number of students who have three or more siblings is .