Find the value of y when x equals 11 .
7x-9y=23

7x - 9y = 23         x = 11

7*11 - 9y = 23

77 - 9y = 23

-9y = 23 - 77

-9y = - 54

y = -54/-9

y = 6

I hope this explains it.

Let’s work this out.

If there are 200 identical cubes packed into a rectangular prism, the total volume of the rectangular prism would be the volume of all of the cubes inside of it. If you took all 200 of those neatly stacked cubes outside of the original rectangular prism, it would be the same volume and look the same as the rectangular prism.

200 • [volume of each cube] = volume of rectangular prism

Each edge length of one of the cubes 1/5 inch, or 0.2 inch. To find the volume of a cube, you follow the formula s•s•s or s^3 (s cubed) where ‘s’ is the side length of the cube. 0.2 cubes or 0.2•0.2•0.2 is equal to 0.008. Th volume of each cube is 0.008 cubic inches.

Great, now what next? To find the volume of the rectangular prism, you must find the total volume of all of the cubes combined (200). 200 cubes times 0.008 cubic inches per cube equals 1.6 cubic inches in total.

200 • 0.008 = 1.6

So, the volume of the rectangular prism is 1.6 cubic inches. :)