Can somebody help me with these two? Thank you!

Adding and subtracting matricesfind the value of each variable. x = and y = would

Mary works for a company that ships packages and must measure the size of each box that needs to be shipped. mary measures a box and finds the length is 7 inches, the width is 14 inches, and the height is 15 inches. what is the volume of the box? [type your answer as a number.]

Which set of lengths could represent the sides of a triangle? a. 3, 7, 10 b. 4, 5, 10 c. 6, 8, 14 d. 12, 6, 7