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2 years ago

Rebecca solved

Mathematics

1 answer:

Nuetrik [128]2 years ago

8 0

No.

$\sqrt{45}=3\sqrt{5} \\2\sqrt{20} =2\sqrt5}$

If you add them up you DO NOT GET $5\sqrt{5}.$ According to mathematics, it equals to $7\sqrt{5}$ .

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A medicine prescription reads "V tabs twice a day."How many tablets must be taken at each time?

Svet_ta [14]

Answer:10 Tablets must be taken

Step-by-step explanation:

V=5

5×2=10

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3 years ago

What percent of 82 is 7

katovenus [111]

Answer: 8.5%

7/82=0.0853

Multiply by 100 to get percentage

0.0853 x 100 = 8.53

7 0

2 years ago

Find an expression for the nth term -3 , 2 , 7, 12

slavikrds [6]

Answer:

5n-8

Step-by-step explanation:

Because this is an arithmetic progression, there is simply an addend that is being added to every number. Because that is 5, the expression, for now, would be 5n. However, the progression does not start at 0, so we will have to subtract 3, and then it would be 5n - 3. We're still not at the answer; this is because the first term starts at 1, not 0. We will have to account for that, so subtract the coefficient, or 5, from the whole expression. That would be 5n - 8, and that would be the answer.

4 0

2 years ago

Who’s right? And why?

kvasek [131]

Answer: Raymond is correct

The DJ charges $75 an hour.

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Explanation:

x = number of hours

y = total cost

The DJ does a 3-hour event for $275. This means one point is (x,y) = (3,275)

Another point is (5,425) because a 5-hour event costs $425.

Let's find the slope of the line through these two points.

$(x_1,y_1) = (3,275) \text{ and } (x_2,y_2) = (5,425)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{425 - 275}{5 - 3}\\\\m = \frac{150}{2}\\\\m = 75\\\\$

The slope is 75, meaning that each time y goes up by 75, x goes up by 1.

Flipped around it means each time x goes up by 1, y goes up by 75.

This means each time we add on an extra hour, the cost goes up by $75.

The DJ charges $75 an hour. Raymond is correct.

3 0

1 year ago

Solve the matrix equation for a, b, c, and d. [1 2] [a b] [6 5][3 4] [c d]= [19 8]

Anit [1.1K]

Answer:

The answer is " $\bold{\left[\begin{array}{cc}a&b\\c&d\end{array}\right] = \left[\begin{array}{cc}7&-2\\ -\frac{1}{2}&\frac{7}{2}\end{array}\right]}$ ".

Step-by-step explanation:

$\bold{\left[\begin{array}{cc}1&2\\3&4\end{array}\right] \left[\begin{array}{cc}a&b\\c&d\end{array}\right] = \left[\begin{array}{cc}6&5\\ 19&8\end{array}\right]}$

Solve the L.H.S part:

$\left[\begin{array}{cc}1&2\\3&4\end{array}\right] \left[\begin{array}{cc}a&b\\c&d\end{array}\right]\\\\\\\left[\begin{array}{cc}a+2c&b+2d\\3a+4c&3b+4d\end{array}\right]$

After calculating the L.H.S part compare the value with R.H.S:

$\left[\begin{array}{cc}a+2c&b+2d\\3a+4c&3b+4d\end{array}\right]= \left[\begin{array}{cc}6&5\\ 19&8\end{array}\right]} \\\\$

$\to a+2c =6....(i)\\\\\to b+2d =5....(ii)\\\\\to 3a+4c =19....(iii)\\\\\to 3b+4d = 8 ....(iv)\\\\$

In equation (i) multiply by 3 and subtract by equation (iii):

$\to 3a+6c=18\\\to 3a+4c=19\\\\\text{subtract}... \\\\\to 2c = -1\\\\\to c= - \frac{1}{2}$

put the value of c in equation (i):

$\to a+ 2 (- \frac{1}{2})=6\\\\\to a- 2 \times \frac{1}{2}=6\\\\\to a- 1=6\\\\\to a =6 +1\\\\\to a = 7\\$

In equation (ii) multiply by 3 then subtract by equation (iv):

$\to 3b+6d=15\\\to 3b+4d=8\\\\\text{subtract...}\\\\\to 2d = 7\\\\\to d= \frac{7}{2}\\$

put the value of d in equation (iv):

$\to 3b+4 (\frac{7}{2})=8\\\\\to 3b+4 \times \frac{7}{2}=8\\\\\to 3b+14=8\\\\\to 3b =8-14\\\\\to 3b = -6\\\\\to b= \frac{-6}{3}\\\\\to b= -2$

The final answer is " $\bold{\left[\begin{array}{cc}a&b\\c&d\end{array}\right] = \left[\begin{array}{cc}7&-2\\ -\frac{1}{2}&\frac{7}{2}\end{array}\right]}$ ".

4 0

3 years ago