Take Saturdays total of $620 and subtract Fridays total of $460 to get $160. Divide that by the difference of the number of pies sold on Friday and Saturday to get $8. Take the $8 and multiply by number of pies sold on Friday (20) to get $160. Take that number and subtract it from the total sold on Friday ($460) to get $300. Divide that by how many cakes were sold on Friday (30) and get $10.
So therefore:
Pies - $8 each
Cakes - $10 each
That's <u>always</u> true if <em>either</em> the exponent <em>or </em>the base is less than ' 1 '.
(But not always of they both are.)