All categories

3 years ago

Long ago, in some town, a phone number consisted of a letter followed by 3 digits (e.g. K651). How many

Mathematics

1 answer:

Readme [11.4K]3 years ago

7 0

Answer:

25978

Step-by-step explanation:

There are 26 letters in the alphabet and 999 numbers with 3 digits so I multiplied and got the answer

Please mark Brainlest if I helped

You might be interested in

Find the? inverse, if it? exists, for the given matrix.<br><br> [4 3]<br><br> [3 6]

True [87]

Answer:

Therefore, the inverse of given matrix is

$=\begin{pmatrix}\frac{2}{5}&-\frac{1}{5}\\ -\frac{1}{5}&\frac{4}{15}\end{pmatrix}$

Step-by-step explanation:

The inverse of a square matrix $A$ is $A^{-1}$ such that

$A A^{-1}=I$ where I is the identity matrix.

Consider, $A = \left[\begin{array}{ccc}4&3\\3&6\end{array}\right]$

$\mathrm{Matrix\:can\:only\:be\:inverted\:if\:it\:is\:non-singular,\:that\:is:}$

$\det \begin{pmatrix}4&3 \\3&6\end{pmatrix}\ne 0$

$\mathrm{Find\:2x2\:matrix\:inverse\:according\:to\:the\:formula}:\quad \begin{pmatrix}a\:&\:b\:\\ c\:&\:d\:\end{pmatrix}^{-1}=\frac{1}{\det \begin{pmatrix}a\:&\:b\:\\ c\:&\:d\:\end{pmatrix}}\begin{pmatrix}d\:&\:-b\:\\ -c\:&\:a\:\end{pmatrix}$

$=\frac{1}{\det \begin{pmatrix}4&3\\ 3&6\end{pmatrix}}\begin{pmatrix}6&-3\\ -3&4\end{pmatrix}$

$\mathrm{Find\:the\:matrix\:determinant\:according\:to\:formula}:\quad \det \begin{pmatrix}a\:&\:b\:\\ c\:&\:d\:\end{pmatrix}\:=\:ad-bc$

$4\cdot \:6-3\cdot \:3=15$

$=\frac{1}{15}\begin{pmatrix}6&-3\\ -3&4\end{pmatrix}$

$=\begin{pmatrix}\frac{2}{5}&-\frac{1}{5}\\ -\frac{1}{5}&\frac{4}{15}\end{pmatrix}$

Therefore, the inverse of given matrix is

$=\begin{pmatrix}\frac{2}{5}&-\frac{1}{5}\\ -\frac{1}{5}&\frac{4}{15}\end{pmatrix}$

4 0

4 years ago

Round to the nearest dime: $3.489

mr_godi [17]

3.49 is the anwser you need

5 0

4 years ago

Which digit could be the ten millions place that is less than 55,000,000 but greater than 25,000,000

Keith_Richards [23]

The answer is B hope this helped

8 0

4 years ago

The first three steps in determining the solution set of the system of equations algebraically are shown.

Ivenika [448]

(2,-1), (-4,17).

Step-by-step explanation:

Equate the equation A and equation B

Convert the quadratic equation in factored form

Group terms that contain the same variable, and move the constant to the opposite side of the equation

Complete the square. Remember to balance the equation by adding the same constants to each side.

Rewrite as perfect squares

Square root both sides

Find the values of y

Substitute the value of x in the equation B

3 0

3 years ago

If t+8= -12, what is the value of t+1

forsale [732]

T = -20 so
t+1= -20 + 1
= -19

5 0

3 years ago