How do I solve this?
1 answer:
Answer:
x ≈ -4.419
Step-by-step explanation:
Separate the constants from the exponentials and write the two exponentials as one. (This puts x in one place.) Then use logarithms.
0 = 2^(x-1) -3^(x+1)
3^(x+1) = 2^(x-1) . . . . . add 3^(x+1)
3×3^x = (1/2)2^x . . . . .factor out the constants
(3/2)^x = (1/2)/3 . . . . . divide by 3×2^x
Take the log:
x·log(3/2) = log(1/6)
x = log(1/6)/log(3/2) . . . . . divide by the coefficient of x
x ≈ -4.419
_____
A graphing calculator is another tool that can be used to solve this. I find it the quickest and easiest.
_____
<em>Comment on alternate solution</em>
Once you get the exponential terms on opposite sides of the equal sign, you can take logs at that point, if you like. Then solve the resulting linear equation for x.
(x+1)log(3) = (x-1)log(2)
x=(log(2)+log(3))/(log(2)-log(3))
You might be interested in
First, simplify
Second, simplify
Third, simplify
Fourth, regroup terms. / Your problem should look like: 6 -
Fifth, multiply both sides by 7. / Your problem should look like: 42 - x = 126
Sixth, subtract 42 from both sides. / Your problem should look like: -x = 126 - 42
Seventh, simplify 126 - 42 to 84. / Your problem should look like: -x = 84
Eighth, multiply both sides by -1. / Your problem should look like: x = -84
Answer: x = -84
Answer:
405
Step-by-step explanation:
To find sample size, use the following equation, where n = sample size, za/2 = the critical value, p = probability of success, q = probability of failure, and E = margin of error.
The values that are given are p = 0.84 and E = 0.03.
You can solve for the critical value which is equal to the z-score of (1 - confidence level)/2. Use the calculator function of invNorm to find the z-score. The value will given with a negative sign, but you can ignore that.
(1 - 0.9) = 0.1/2 = 0.05
invNorm(0.05, 0, 1) = 1.645
You can also solve for q which is 1 - p. For this problem q = 1 - 0.84 = 0.16
Plug the values into the equation and solve for n.
Round up to the next number, giving you 405.