0.625
divide 5 by 8 is 0.625 rounded would be 0.63
The answer is 28 years
At = A0 * e^(-k * t)
At = 12 g
A0 = 15 g
k = 7.9 × 10^-3 = 0.0079
t = ?
12 = 15 * e^(-0.0079 * t)
12/15 = e^(-0.0079 * t)
0.8 = e^(-0.0079 * t)
Logarithm both sides (because ln(e) = 1:
ln(0.8) = ln(e^(-0.0079 * t))
ln(0.8) = (-0.0079 * t) * ln(e)
-0.223 = -0.0079 * t
t = -0.223 / -0.0079
t = 28.23
t ≈ 28 years
Answer:
Width=4, and Length=17
Step-by-step explanation:
first you will make a variable for the width which i will say is x
now make it an equation (3x+5) (x) = 68
then solve 3x^2+5x=68
then 3x^2+5x-68=0
then x=4
then you have to substitute so 3(4)+5= 17 and 4
The answer would be $3 becaus of x = $12 and y = $9. $12 - $9 = $3.