2x + 14 = 90
2x + 14 - 14 = 90 - 14
2x = 76
x = 38
Answer:
If you have a quantity X of a substance, with a decay constant r, then the equation that tells you the amount of substance that you have, at a time t, is:
C(t) = X*e^(-r*t)
Now, we know that:
We have 2000g of substance A, and it has a decay constant of 0.03 (i assume that is in 1/year because the question asks in years)
And we have 3000 grams of substance B, with a decay constant of 0.05.
Then the equations for both of them will be:
Ca = 2000g*e^(-0.03*t)
Cb = 3000g*e^(-0.05*t)
Where t is in years.
We want to find the value of t such that Ca = Cb.
So we need to solve:
2000g*e^(-0.03*t) = 3000g*e^(-0.05*t)
e^(-0.03*t) = (3/2)e^(-0.05*t)
e^(-0.03*t)/e^(-0.05*t) = 3/2
e^(t*(0.05 - 0.03)) = 3/2
e^(t*0.02) = 3/2
Now we can apply Ln(x) to both sides, and get:
Ln(e^(t*0.02)) = Ln(3/2)
t*0.02 = Ln(3/2)
t = Ln(3/2)/0.02 = 20.3
Then after 20.3 years, both substances will have the same mass.
Boardgame+snacks=total weight
total weight<25
boardgame=4
snacks=weight per each time number=14 times n or 14n
4+14n<25
minus 4 both sides
14n<21
divide both sides by 14
n<1.5
we can't send 0.5 package so we round down
n<1
send less than 1 snack pack
A
The answer would be 100/101 if we follow according to the rule on which the sequence is based on!
Luis is finding 5 because 9 minus 6 is 3. 3 plus 2 equal 5 easy
