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3 years ago

7 - 2x if x = -4 And show your work

Mathematics

1 answer:

uysha [10]3 years ago

8 0

Answer: 15

Step-by-step explanation: To evaluate an expression, we plug the value of the variable into the expression and simplify.

Since we have 7 - 2x and x is -4, we have 7 - 2(-4).

Simplifying from here, 2(-4) is -8 so we have 7 - (-8).

Now, remember that a a minus sign followed by a

negative sign turns the two signs into a plus sign.

So 7 - (-8) can be thought of as 7 + (+8) which is 15.

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What is the slope of the line through the points (2, 4) and (2, -11)?

Shkiper50 [21]

Answer:

The slope of the line would be undefined

Step-by-step explanation:

First you take the y of the second point and subtract it from the y of the first point. -11 - 4. That leaves you with -15. Then you take the x of the second point and subtract it from the x of the first point. that leaves you with 0. Then you put y over x. You then have -1`5/0. That is undefined.

8 0

3 years ago

Philip made a total of 9 bracelets and necklaces from 120 inches of cord. He used 8 inches of cord for each bracelet and 20 inch

Viktor [21]

Answer:

So Philip made 5 bracelets and 4 necklaces.

Step-by-step explanation:

Let x = number of bracelets and y = number of necklaces.

Since we have a total of 9 bracelets and necklaces,

x + y = 9 (1)

Also, we have 8 inches of cord for each bracelet and 20 inches of cord for each necklace, then the total length for the bracelet is 8x and that for the necklace is 20y.

So, the total length for both is 8x + 20y. Since the total length of cord used is 120 inches,

8x + 20y = 120 (2)

Simplifying it we have

2x + 5y = 30 (3).

Writing equations (1) and (3) in matrix form, we have

$\left[\begin{array}{ccc}1&1\\2&5\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}9\\30\end{array}\right]$

Using Cramer's rule to solve for x and y,

$x = det \left[\begin{array}{ccc}9&1\\30&5\end{array}\right] /det \left[\begin{array}{ccc}1&1\\2&5\end{array}\right] \\$

x = (9 × 5 - 30 × 1) ÷ (1 × 5 - 1 × 2)

x = (45 - 30) ÷ (5 - 2)

x = 15 ÷ 3

x = 5

$y = det \left[\begin{array}{ccc}1&9\\2&30\end{array}\right] /det \left[\begin{array}{ccc}1&1\\2&5\end{array}\right] \\$

y = (30 × 1 - 9 × 2) ÷ (1 × 5 - 1 × 2)

y = (30 - 18) ÷ (5 - 2)

y = 12 ÷ 3

y = 4

So Philip made 5 bracelets and 4 necklaces.

3 0

3 years ago

Please help! Will give brainliest :)

Vedmedyk [2.9K]

Answer:

15 boys in 3 groups

15 girls in 4 groups

Step-by-step explanation:

60 ÷ 4 = 15

45 ÷ 3 = 15

Have an awesome day! :D

7 0

3 years ago

Why would 6% as a fraction be 6/100?

dangina [55]

Well, percent (%) means per hundred, and your number is 6. Therefore, you have 6 per hundred, or 6/100. Also, when you have a percent and want to convert it into a fraction, you must divide the percent by 100, so you could just put the six over 100 since the line between the numerator and denominator basically means division.

3 0

4 years ago

Jocelyn just accepted a job at a new company where she will make an annual salary of $70000 . Jocelyn was told that for each yea

REY [17]

Answer:82000

1500t+70000

7 0

3 years ago