#### Answer

144;120

#### Work Step by Step

The expression would be 0.8(200-y).Y represents age in years.
20-year-old person:
0.8(200-y) -plug in 20 for y-
0.8(200-20) -simplify-
0.8(180) -multiply-
=144
50-year-old person:
0.8(200-y) -plug in 50 for y-
0.8(200-50) -simplify-
0.8(150) -multiply-
=120