Cho hàm số 3 biến. Hỏi có bao nhiêu đạo hàm riêng cấp 3

Solve |x| > -9 a) {x|x< -9 or x> 9} b) all reals c) no solution

The verbal translation for the difference of m and 7 increased by 15

The length of the line segment joining the midpoints of sides ab and bc of the parallelogram abcd is 10. find the length of diagnol ac