Ask question

Ask question

All categories

max2010maxim [7]

3 years ago

6

Tyrone practices the piano for 120 min each week. Amina practices the piano 45% of the time that Tyrone practices each week. How

many minutes does Amina practice the piano each week?

1 answer:

Margaret [11]3 years ago

6 0

Answer:

Amina practices the piano for 54 minutes each week.

Step-by-step explanation:

45% * 120min = 0.45 * 120min = 9/20 * 120min = 9 * 6min = 54min

You might be interested in

22.857142857142858 As a fraction

Mamont248 [21]

Answer:

Step-by-step explanation:

1. The answer is 8/35.

2. This works because 8/35 equals 22.857142857142858.

Please give me brainliest, I really need it! Thank you!

5 0

1 year ago

What is the measure of angle K in degrees?

maxonik [38]

The measure is 30° degrees

5 0

3 years ago

Read 2 more answers

Solve for XX. Assume XX is a 2×22×2 matrix and II denotes the 2×22×2 identity matrix. Do not use decimal numbers in your answer.

sveticcg [70]

The question is incomplete. The complete question is as follows:

Solve for X. Assume X is a 2x2 matrix and I denotes the 2x2 identity matrix. Do not use decimal numbers in your answer. If there are fractions, leave them unevaluated.

$\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ · X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ =<em>I</em>.

First, we have to identify the matrix <em>I. </em>As it was said, the matrix is the identiy matrix, which means

<em>I</em> = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

So, $\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ · X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Isolating the X, we have

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{cc}2&8\\-6&-9\end{array}\right]$ - $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

Resolving:

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}2-1&8-0\\-6-0&-9-1\end{array}\right]$

X· $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ = $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Now, we have a problem similar to A.X=B. To solve it and because we don't divide matrices, we do X=A⁻¹·B. In this case,

X= $\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ ⁻¹· $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Now, a matrix with index -1 is called Inverse Matrix and is calculated as: A . A⁻¹ = I.

So,

$\left[\begin{array}{ccc}9&-3\\7&-6\end{array}\right]$ · $\left[\begin{array}{ccc}a&b\\c&d\end{array}\right]$ = $\left[\begin{array}{ccc}1&0\\0&1\end{array}\right]$

9a - 3b = 1

7a - 6b = 0

9c - 3d = 0

7c - 6d = 1

Resolving these equations, we have a= $\frac{2}{11}$ ; b= $\frac{7}{33}$ ; c= $\frac{-1}{11}$ and d= $\frac{-3}{11}$ . Substituting:

X= $\left[\begin{array}{ccc}\frac{2}{11} &\frac{-1}{11} \\\frac{7}{33}&\frac{-3}{11} \end{array}\right]$ · $\left[\begin{array}{ccc}1&8\\-6&-10\end{array}\right]$

Multiplying the matrices, we have

X= $\left[\begin{array}{ccc}\frac{8}{11} &\frac{26}{11} \\\frac{39}{11}&\frac{198}{11} \end{array}\right]$

6 0

3 years ago

A jar contains 46 quarters and pennies. The total value of the coins is $4.30. Which system of equations can be used to find p,

Crazy boy [7]

Answer:

16 quarters

30 pennies

Step-by-step explanation:

q= quarters

p=pennies

set up a system of equations. One equation is for total value, the other is total # of coins.

q + p = 46

0.25q + 0.01p = 4.30 -> multiply this equation by 4 so you can subtract from the top equation

q + P =46

1q + 0.04p = 17.20

subtract the bottom equation from the top

0.96p = 28.8

divide by 0.96

p=30

substitute p in the top equation

q + 30 = 46

subtract 30 from both sides

q = 16

4 0

3 years ago

Which function is a translation of the parent absolute value function?f(x) = 2X1 f(x) = (x+61f(x) = |x|F(x) = -4X1

artcher [175]

Answer

Explanation

Translations move the parent function toward the left, right, downwards or upwards.

f(x) = 2 |x|

This stretches the function by a factor of 2, hence, it is not a translation.

f(x) = |x + 6|

This translates the parent absolut value functio

8 0

1 year ago