1. how many cubic blocks of side length 1/7 inch would it take to fill a cube with a side length of 3/7 inch? 2. how many cubic blocks of side length 1/7 inch would it take to fill a rectangular prism with a length, width, and height of 3/7 inch, 1/7 inch, and 3/7 inch, respectively? 3.how many cubic blocks of side length 1/6 inch would it take to fill a cube with a side length of 2/6 inch?

To find how many blocks it would take in each of these scenarios, you could find the total volume and then divide by the volume of each smaller cube.

1.  3/7 x 3/7 x 3/7 = 27/343 cubic inches
     1/7 x 1/7 x 1/7 = 1/343 cubic inches

27/343 cubic inches  divided by 1/343 cubic inches = 27 cubes.

2.  3/7 x 1/7 x 3/7 = 9/343 cubic inches
9/343 cubic inches divided into groups of 1/343 cubic inches is 9 cubes.

3.  2/6 x 2/6 x 2/6 = 8/216 cubic inches
8/216 cubic inches divided by 1/216 cubic inches is 8 cubes.

Another way to think of it would be for #1, each 3/7 of an inch would be 3 groups of 1/7, so 3 x 3 x 3 for each dimension would result in 27 cubes.

For #2, it would be 3 groups of 1/7, one group of 1/7 and another 3 groups of 1/7, so 3 x 3 is 9 cubes.

For #3 it would be 2 groups of 1/6 three times, so 2 x 2 x 2 = 8 cubes.
   
   

6(2x + 5y)6 (2x) = 12x6 (5y) = 30y12x + 30y

It’s hard to understand what you put.. can you show a picture ?