A raise of 20% would raise Laura's salary to $60,000 ($50,000 × 1.2) - we multiply by 1.2 because 1.2 = 120% which is her new salary compared to her old one ($50,000 is 100% and $60,000 is now 120%)
15% of her new salary is $9,000 ($60,000 × 0.15) - we multiply by 0.15 because 0.15 = 15% which is what we are finding of her new salary
At the end of the year Laura has $51,000 ($60,000 - $9,000)
