Klaus was replacing the roof on his house. he used 420 nails to attach all the pieces. each pieces of wood needed 7 nails to hold it he used 40 pieces of wood. how many pieces were left?

For the equations below which statement is true ? -2x=14 6x=-42

Hector and alex traded video games. alex gave hector one fourth of his video games in exchange for 6 video games. then he sold 3 video games and gave 2 video games to his brother. alex ended up with 16 video games. how many video games did alex have when he started?

The base of a rectangular pyramid is 13 inches long and 12 inches wide. the height of the pyramid is 8 inches. what is the volume of the pyramid