## Algebra 1: Common Core (15th Edition)

$a=percentage \times base$ (formula for finding a base) Base 1: $3000=.15 \times b$ (Divide 3000 by .15) b=20,000 Base 2: $3600=.15 \times b$ (Divide 3600 by .15) b=24,000 $24,000-20,000=4000$ There is a difference of 4000.