China has 4,321 million animals. write this number in standard form.

Which statement is not always true for a parallelogram? (a) opposite sides are congruent. (b) diagonals bisect each other. (c) it has 4 congruent angles. (d) consecutive angles are supplementary.

Find and simplify an expression for the area of five rows of x squares with side lengths of x centimeters.

What are the greatest common factor of 75 and 30