Basic formula of junior algebra 3^(2x+1)=12 x=?

3^(2x+1)=(3^2x)*3=12
3^2x=4 3^x=2 x=lg2/lg3=0.6309298
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If x = 2.2618, 3 ^ (2x + 1) = 3 ^ 5.5236 > 3 ^ 5

A summary of formulas for junior high school algebra

A junior high school algebra formula. I forgot
The zeroth power of n =?
The - 1 power of n (cube) =?
The - 1 / 2 power of n (cube) =?
1 / 2 power of n (cubic) =?
Give an official answer. In addition, give an example for each formula. The example that n is greater than 1 and less than 10 is required

The zeroth power of n is equal to 1
The - 1 power of n is equal to 1 / n
The 1 / 2 power of n is equal to the root 2
The - 1 / 2 power of n is equal to 1 / 2 of the root sign

All the algebraic formulas of mathematics in grade one and grade two of junior middle school

I only remember these complete square formulas: (a + b) = a + 2Ab + B (a-b) = a-2ab + b square difference formulas: (a + b) (a-b) = a-b

Take any three numbers from 1, 2, 3, 4 and 5 to form three numbers without repeated numbers. Find out the probability that the three digits are even and the three numbers are greater than 400?

Write all the numbers that meet the conditions by exhaustive method
412,432,452
512,532,542
514,524,534
Nine in all
The total number of three digits without repetition is a (5,3) = 60
The probability that this three digit number is even and that these three numbers are greater than 400 is 9 / 60 = 3 / 20

Take any two numbers from the natural number 1, 2, 3 and 4, and find out the probability that both numbers are odd; find out the probability that both numbers are odd or even

The same odd probability is one sixth, the same odd or even probability is one third!

Take any 4 of the 10 numbers from 0 to 9 that are not repeated, and find the probability that (1) can form a 4-bit odd number and (2) can form a 4-bit even number
The main reason is that the formula has the best analysis

Any four are in the order of thousand, hundred, ten and ten
The first digit of 4 digits (thousand digits) cannot be 0
(1) The probability of forming a 4-bit odd number is 5 / 10-1 / 10 * 5 / 9 = 45 / 90-5 / 90 = 4 / 9
(2) The probability of forming a 4-bit even number is 5 / 10-1 / 10 * 4 / 9 = 45 / 90-4 / 90 = 41 / 90

There are 2n numbers, half of which are odd and half even. If you take any two numbers from them, the probability that the sum of the two numbers is even is ()
A. 12B. 12nC. n−12n−1D. n+12n+1

According to the meaning of the question, there are 2n numbers, including n odd numbers and n even numbers, from which any two numbers can be taken. There are C2N2 cases. If the sum of the two numbers is even, then the two numbers taken are odd or even, and there are 2cn2 cases in total. According to the classical probability formula, the probability is 2c2nc22n = n − 12n − 1, so C

The probability that the product of multiplication of two different numbers from five odd numbers is even is zero

0 because you choose an odd number. If you multiply an odd number by an odd number, you get an odd number. If you divide any number by zero, you get zero

Take any four of the ten numbers from 0 to 9 to find the probability of forming an even number

50%

Basic formula of junior algebra 3^(2x+1)=12 x=?