In Store A the price of mayonnaise went
down from $4.31 to $3.71. In Store B, it went
from $8.09 to $7.23. In Store C it went from
$8.07 to $3.53.

1. ∠1 is complementary to ∠2 and ∠3 is complementary to ∠2. subtraction property of equality 2. m∠1 + m∠2 = 90 and m∠3 + m∠2 = 90 substitution 3. m∠1 + m∠2 = m∠3 + m∠2 definition of complementary 4. m∠1 = m∠3 given