Answer:
A 6.4
Step-by-step explanation:
(4/5)/(1/8) this is the answer
Answer:
hi, need help with anything?
Step-by-step explanation:
Answer:
r = 3.5 * .5^(t/65); around 117.5 days
Step-by-step explanation:
r = remaining substance
t = time in days
The half life is 65 day, meaning the .5 must be put to a power of t/65.
The initial substance was 3.5, which we must substitute in.
After using logarithms to solve our new equation, we are left with t=(about)117.5 days for there to be less than 1 gram of substance remaining.
Recall that given the equation of the second degree (or quadratic)
ax ^ 2 + bx + c
Its solutions are:
x = (- b +/- root (b ^ 2-4ac)) / 2a
discriminating:
d = root (b ^ 2-4ac)
If d> 0, then the two roots are real (the radicand of the formula is positive).
If d = 0, then the root of the formula is 0 and, therefore, there is only one solution that is real and of multiplicity 2 (it is a double root).
If d <0, then the two roots are complex and, in addition, one is the conjugate of the other. That is, if one solution is x1 = a + bi, then the other solution is x2 = a-bi (we are assuming that a, b, c are real).
One solution:
A cut point with the x axis
Two solutions:
Two cutting points with the x axis.
Complex solutions:
Does not cut to the x axis
So you have some initial amount x and we want to know how long it will take with compound interest to triple our original amount x (so 3x). The equation sets up like 3x(the amount we want)= x(original amount) times 1.062(the interest increase)^t So 3x=x(1.062)^t where t is the amount of years. When you divide both sides by x it cancels out and you end up with 3=1.062^t. Take the natural log of both sides. Ln(3) = Ln(1.062^t) and the t being an exponent can come in front of the the natural log. Ln(3) = t(Ln(1.062)) Divide both sides by (Ln(1.062)),. Ln(3)/Ln(1.062)=t. And you should just plug that into a calculator to find t.
