Help meee what is 2 + 2=

What constants do you need to add to each of the following quadratic equations to complete the square? 2x2 - 3x = 0 x2 - 8x = 0 2x2 - 11x = 18

What is the volume of this square pyramid?

Which three lengths could be the lengths of the sides of a triangle? 21 cm, 7 cm, 7 cm 9 cm, 15 cm, 22 cm 13 cm, 5 cm, 18 cm 8 cm, 23 cm, 11 cm