1a:
580 - (580 × .1) - 20
580 - (58) - 20
522 - 20
502
1b:
990 - (990 × .25) - 20
990 - (247.5) - 20
742.5 - 20
722.5
I'm not sure how to solve #2.
Answer:
x = 7
Step-by-step explanation:
x = age
200 - 3x = 47, solve for x
x =51