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3 years ago

Please help me i’m desperateeee!!!

Mathematics

1 answer:

lara31 [8.8K]3 years ago

7 0

Answer:

option no.D

6y+15x

Step-by-step explanation:

hope it helps

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Marlena has $74 in a checking account and downloads 14 equally priced albums from Itunes. She pays with a check and now has -$52

Evgesh-ka [11]

She has $74 and now -$52, she gone to 0 and to -52, so she spends 74 + 52 = $126

Now let's see

14 albums ---------------------------------- $126

1 album ----------------------------------------- $x

14 . x = 1 . 126

14x = 126

x = 126/14

x = 9

Each album costs $9

5 0

4 years ago

Exercise 3.3.2: Verify that the system x® 0 1 3 3 1 x® has the two solutions 1 1 e 4t and 1 −1 e −2t a) . b) Write down the gene

nikklg [1K]

Answer:

The general solution of the system is

$X(t)=A\left(\begin{array}{c}1 &-1 \end{array}\right)e^{-2t} + B\left(\begin{array}{c}1 &1 \end{array}\right)e^{4t}\\$

Step-by-step explanation:

To verify that the system $X^{'} =\left[\begin{array}{cc}1&3\\3&1\end{array}\right] X$ has the solutions given,

First, we determine the Eigen Values β of the matrix of the form $X^{'} =A X$ Using |A-βI|=0, where I is the Identity Matrix, we have:

$|A-\beta I|=0$

$|\left(\begin{array}{cc}1&3\\3&1\end{array}\right )-\left(\begin{array}{cc}\beta &0\\0&\beta \end{array}\right )|=0$

Subtracting matrices

$\left|\begin{array}{cc}1-\beta &3\\3&1-\beta \end{array}\right |=0$

Taking the determinant

$(1-\beta)(1-\beta)-(3X3)=0\\1-\beta-\beta+\beta^{2}-9=0\\\beta^{2}-2\beta-8=0\\\beta^{2}-4\beta+2\beta-8=0\\\beta(\beta-4)+2(\beta-4)=0\\(\beta-4)((\beta+2)=0\\\beta=4 or -2$

We determine the eigen vector using $\left(\begin{array}{cc}1-\beta &3\\3&1-\beta \end{array}\right)\left(\begin{array}{c}c_{11} &c_{12} \end{array}\right)=0$

When $\beta$ = -2,

$\left(\begin{array}{cc}3 &3\\3&3 \end{array}\right)\left(\begin{array}{c}c_{11} &c_{12} \end{array}\right)=0$ which implies that $3c_{11}+3c_{12}=0$ and thus

$If c_{11}=1, c_{12}=-1$

When $\beta$ = 4,

$\left(\begin{array}{cc}-3 &3\\3&-3 \end{array}\right)\left(\begin{array}{c}c_{21} &c_{22} \end{array}\right)=0$ which implies that $3c_{21}-3c_{22}=0$ and thus

$If c_{21}=1, c_{22}=1$

A general solution of the system is given as

$X(t)=Ac_{1}e^{\beta _{1}} + Bc_{2}e^{\beta _{2}t$ where the c's are the eigen vectors.

Thus the general solution is

$X(t)=A\left(\begin{array}{c}1 &-1 \end{array}\right)e^{-2t} + B\left(\begin{array}{c}1 &1 \end{array}\right)e^{4t}\\$

7 0

3 years ago

Write log7(2 ⋅ 6) + log73 as a single log. Log Subscript 7 Baseline 11 Log Subscript 7 Baseline 15 Log Subscript 7 Baseline 36

zhannawk [14.2K]

Answer:

C. log7 36....................................

8 0

3 years ago

Read 2 more answers

Omar scored an 82% on his first test. He scored 38 out of 50 on the second test. Which performance is better? Explain your reaso

omeli [17]

Answer:

82% is greater

Step-by-step explanation:

38/50 = 76/100

76/100 represents 76%

6 0

3 years ago

18. The table shows the amount of money in a savings account after several weeks.

anygoal [31]

Answer:

a. Arithmetic

b. $a_{n} = a_{n-1} + 15$

c. $a_{n} = 15n + 125$

Step-by-step explanation:

A sequence is arithmetic when the difference between one term and the next is a constant. On the other hand, a sequence is geometric when the next term is found by multiplying the previous by a constant.

In this case, the next term of the sequence can be found by adding $15. Therefore, the sequence is <em>ARITHMETIC ✔️</em>

The recursive formula will be the following: $a_{n} = a_{n-1} + 15$

The explicit formula is the following: $a_{n} = 15n + 125$

8 0

3 years ago