You buy 6 videos on sale. the videos are on sale for $8 and $10. you spend $52. how many $8 videos did you buy?

Set up a system of equations:

x + y = 6
8x + 10y = 52

Where 'x' is the number of $8 videos and 'y' is the number of $10 videos.

x + y = 6

Subtract 'x' to both sides:

y = -x + 6

Plug in '-x + 6' for 'y' in the 2nd equation:

8x + 10y = 52

8x + 10(-x + 6) = 52

Distribute 10 into the parenthesis:

8x - 10x + 60 = 52

Combine like terms:

-2x + 60 = 52

Subtract 60 to both sides:

-2x = -8

Divide -2 to both sides:

x = 4

So you bought four $8 videos.