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:
AB = 8/ cos 60
Step-by-step explanation:
We want to find the hypotenuse AB
Since we have a right triangle
cos theta = adj/ hyp
cos 60 = 8/ AB
AB cos 60 = 8
AB = 8/ cos 60
Answer:
67
Step-by-step explanation: Given the quadratic equation $z^2 + bz + c = 0$, Vieta's formulas tell us the sum of the roots is $-b$, and the product of the roots is $c$. Thus,
\[-b = (-7 + 2i) + (-7 - 2i) = -14,\]so $b = 14.$
Also,
\[c = (-7 + 2i)(-7 - 2i) = (-7)^2 - (2i)^2 = 49 + 4 = 53.\]Therefore, we have $b+c = \boxed{67}$.
There are many other solutions to this problem. You might have started with the factored form $(z - (-7 + 2i))(z - (-7 - 2i)),$ or even thought about the quadratic formula.
This is the aops answer :)
