A grocer has a block of cheese that has length 12 inches, width 4 inches and height 3 inches. Then he slices the cheese into two equal triangular prisms. What will be the length of the of the rectangular cross-section? (If necessary, round your answer to the nearest inch.)

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -

is there supposed to be a picture here?