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2 years ago

A teacher has 21 red pens. If the ratio of red pens to blue pens she owned was 3:1 , how many pens did she have total?

Mathematics

1 answer:

Kobotan [32]2 years ago

5 0

21/3 is 7 so there are 7 pens for every 1 ratio
7 x 1 = 7
21+7 = 28

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5/6(2x+12)-8=4-(x+1)

alekssr [168]

For this case we have the following equation:

$\frac {5} {6} (2x + 12) -8 = 4- (x + 1)$

We apply distributive property on the left side of the equation:

$\frac {5 * 2} {6} x + \frac {5 * 12} {6} -8 = 4- (x + 1)\\\frac {10} {6} x + \frac {60} {6} -8 = 4- (x + 1)$

We simplify the left side of the equation:

$\frac {5} {3} x + 10-8 = 4- (x + 1)$

Different signs are subtracted and the major sign is placed.

$\frac {5} {3} x + 2 = 4- (x + 1)$

On the right side we must take into account that:

$- * + = -$

So:

$\frac {5} {3} x + 2 = 4-x-1\\\frac {5} {3} x + 2 = 3-x$

We add x to both sides of the equation:

$\frac {5} {3} x + x + 2 = 3\\\frac {5 * 1 + 3 * 1} {3} x + 2 = 3\\\frac {5 + 3} {3} x + 2 = 3\\\frac {8} {3} x + 2 = 3$

We subtract 2 from both sides of the equation:

$\frac {8} {3} x = 3-2\\\frac {8} {3} x = 1$

We multiply by 3 on both sides of the equation:

$8x = 3$

We divide by 8 on both sides of the equation:

$x = \frac {3} {8}$

Thus, the solution of the equation is:

$x = \frac {3} {8}$

Answer:

$x = \frac {3} {8}$

4 0

3 years ago

(Subtract<br> ) f(x) = x + 1<br> g(x) = x2 + 1

kramer

Answer:

The first question:

x = -1

Step-by-step explanation:

Step 1 :

Pulling out like terms :

1.1 Pull out like factors :

-x - 1 = -1 • (x + 1)

Equation at the end of step 1 :

Step 2 :

Solving a Single Variable Equation :

2.1 Solve : -x-1 = 0

Add 1 to both sides of the equation :

-x = 1

Multiply both sides of the equation by (-1) : x = -1

One solution was found :

x = -1

Processing ends successfully

plz mark me as brainliest :)

7 0

2 years ago

The question is asking me what’s the slope and is giving me 4 options and it’s very difficult

Andreas93 [3]

The answer to your question is C

6 0

2 years ago

Read 2 more answers

ATM stands for Automated Teller Machine.

lakkis [162]

This statement is true.

5 0

3 years ago

Charlie’s portfolio has an expected annual return at 10%, with an annual standard deviation at 12%. Assume his investment return

Deffense [45]

Answer:

There is a 34.13% probability that the actual return will be between the mean and one standard deviation above the mean.

Step-by-step explanation:

This is problem is solving using the Z-score table.

The Z-score of a measure measures how many standard deviations above/below the mean is a measure. Each Z-score has a pvalue, that represents the percentile of a measure.

What is the probability that the actual return will be between the mean and one standard deviation above the mean?

One measure above the mean is $Z = 1$

The mean is $Z = 0$

This means that this probability is the pvalue of $Z = 1$ subtracted by the pvalue of $Z = 0$ .

$Z = 1$ has a pvalue of 0.8413.

$Z = 0$ has a pvalue of 0.50.

This means that there is a 0.8413-0.50 = 0.3413 = 34.13% probability that the actual return will be between the mean and one standard deviation above the mean.

3 0

3 years ago