# multiplication

1. ### Advanced Matrices and Cryptography Question Help

Hello, I was stuck on the following question. 'Your task it to crack the following code and find the encrypted word. To make your task easier, the following information about the encoding matrix is given: Position 1,1 in the encoding matrix is an even number. The decoding matrix only contains...
2. ### Internal Rate of Return, Simplifying Equation Help

Hi, I have an Internal Rate of Return question I need help with please. I have been given the answer for r, which is 0.208, however I cannot understand how the following equation: -300 + -300/(1+r) + 800/(1+r)^2 = 0 when multiplied by (1+r)^2, becomes: 300r^2 + 900r - 200 = 0 Could someone...
3. ### Show that A is closed under multiplication

(The star indicated multiplication) "Let A = {r*k +1 | k∈Z^+}, Where r is ANY fixed positive integer. Show that A is closed under multiplication." In words: Let A equal the set of r times k plus one, where k is an element of all positive integers. I am very familiar with equations that are...
4. ### Matrix multiplication true / false

A and B are matrices. If A is invertible and AB = 0, then B = 0. Can you prove this is true or use any example to show that it's false? I don't understand how to find a non-zero matrix B that when multiplied by A gives us 0. I know the equation Ax = 0, but I don't know how to apply it to find...
5. ### Independence and Multiplication rule help

Hi guys, I'm back again with another question hopefully you guys can help me. [Question] We have a fuse box with 20 fuses, 5 of which are defective. If 2 fuses are selected at random, in succession, and without replacement, what is the probability that both fuses are defective? [SOLN] A =...
6. ### 5 th grade math - decimal multiplication using models

Hi, This might seem a silly question to you all Math experts. I am having problem understanding the logic here. I understood the process of multiplying decimals using grid. Here's the question: The distance from Charlene's house to her school is 0.8 miles. Charlene rides her bike 7 tenth of...
7. ### Closure Under Scalar Multiplication

When discussing proving whether something is a vector space or sub-space, then this comes up: How to prove closure under scalar multiplication. May I see a simple example, to get a basic idea?
8. ### Multiplication of scientific notation problem

Hi there how would i solve this equation 5.5 Mol x (6.02x10^23 Atoms) / 1 MOL
9. ### Multiplication and Subtraction of logs with different bases.

\text{If }a=\log_{12} 18, b=\log_{24}54\text{, then find the value of }ab+5(a-b) I am trying in different ways to equalize the bases. But I can't do anything as the bases are unequal.
10. ### Different Roots Multiplication

Usually I double the square/cube and halve the root, or double the root and halve the square/cube until they're similar, but I don't know what to do with this one. That's probably the wrong way of going about it, anywho... Answer being 18.

multiply by the formula or vice versa - to determine the polynomial multiplied. 1. (10-3y)2 = 2. (m+3) (m+3) = 3. (5x4y2)2 = 4. (m+n)2 = 5. (s-t)2 = 6. (2a+5)2 = 7. (-a+3c)2 = 8. (-5x-3y)2 = 9. c2 - 2cd + d2 = 10. (10a+2)2 = 11. (3m2 +4n) (3m + 4n) = 12. (5-x) (5-x) = 13. (x-y)2 =...
12. ### Compute binary multiplication without multiplying

Hi all. As the tittle says, the problem is to find a way to compute the result of the multiplication of 2 binary variables without multiplying them. I have 2 binary variables X and Y, such that the summation tables is: X Y X+Y 0 0 0 0 1 1 1 0 1 1 1 2 The subtraction table is: X Y X-Y 0 0 0...
13. ### matrix multiplication

\begin{pmatrix} 2&1\\-4&0\\-3&2\end{pmatrix} \begin{pmatrix} 2 \\ 3 \end{pmatrix} = \begin{pmatrix} 7\\-8\\0 \end{pmatrix} is this correct ?
14. ### S3 multiplication table

1) Do generators exist for S3 (the symmetric group)? I thought the symmetric groups all had generators? 2) When working out products of elements in S3 I get that (231)(213) = (123). This is a product of two 3-cycles and they are not inverses so (123) has to represent a 3-cycle. How do I...
15. ### Question concerning roots and multiplication

if I have 2*sqrt(x) *x, what is the simplifed version of this? The reason I ask is that I am working on a question Online Derivative Calculator ? now with steps! (if you click this link and if it doesn't show the working, just click go) and I can get the answer it says, but not the...
16. ### Multiplication shift cipher with k-graphs

Ok, I've been looking at a worked example of a question I can't understand what's going on a certain point. There is a multiplier of 17, a shift 41 and k=2. PA needs to be enciphered. P has the value of 16 and A has the value of 1. PA is converted to a pair with the sum: 16 x 62 + 1 = 993...