Life expectancy of dollar bill = d
life expectancy of coin = c
d = 1/20 c
substitute value in for c (30)
d = 1/20 * 30
d = 30/20
d = 1.5
life expectancy of a dollar bill = 1.5 years
Answer:
Step-by-step explanation:
the number should be 212.02568593112
Answer:
This system has infinite solutions and it would be much easier to solve it by elimination but substitution it is.
Step-by-step explanation:
-3x+3y=9
-x+y=3
Isolate either x or y in any of the equations. I'll go with the second.
y = 3+x
Now substitute this for y in the first equation.
-3x+3(3+x)=9
Distribute the 3
-3x+9+3x=9
Combine like terms:
9=9
0=0
It's infinite
Answer:
battery costs $5, tax is $1.20, and so the total is $26.20
Step-by-step explanation: