Answer:

Step-by-step explanation:
Given
(5x - 3y)² = 0, then
5x - 3y = 0 ( add 3y to both sides )
5x = 3y (divide both sides by 5 )
x =
y ( divide both sides by y )
= 
1. She could get 9 envelopes for 4 dollars each (or the other way around)
2. She could get 12 envelopes for 3 dollars each (or the other way around)
3. She could get 18 envelopes for 2 dollars each (or the other way around)
Answer:
2.5
Step-by-step explanation:
The constant of probability is 16/6.4=2.5
If I'm right the principal amount is $1,000 and the interest(if $1,550) is $550 in the transaction.