Jane will receive 18% less of her regular pay when she retires. Her regular pay is $500 per week.

a How much would she receive per week if she retires today?
answer: 500/18% = 90 500-90= $410

b. Explain how you can make this same calculation using 100%-18%=82%
answer: same as above

c. show why these calculations are equivalent in general. (Hint: Write an expression for finding an amount A minus n% of A. Write another expression for finding (100-n)% of A and then use algebra to show that these two expressions are the same.)
Don't know the answer for this one.

4 answers

Use n instead of 18% in your first and second calculations.

a.
500*n%=5n
net receipt=500-5n = 500(1-n/100)

b.
100%-n%=(100-n)%
net receipt = 500(100-n)% = 500(1-n/100)

Since a and b are the same, so the two calculations are equivalent for any value of n.
bhj
wutdouthinkboi.
usegoogle
what is the expression for finding an amount a minus n% of a write another expression for finding (100-n)% of a and then use algebra to show that these two expression are the same