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3 years ago

Help plz and thx for your help

Mathematics

1 answer:

Bumek [7]3 years ago

3 0

9514 1404 393

Answer:

Dawn has $1670 in account 1 and $1570 in account 2.

Step-by-step explanation:

Dawn can multiply the second equation by 8 and add 7 times the first equation.

8(3/8A +7/8B) +7(A -B) = 8(2000) +7(100)

10A = 16,700

A = 1670

B = 1570 . . . . 100 less than A

Dawn has $1670 in account 1 and $1570 in account 2.

<em>Check</em>

3/8(1670) +7/8(1570) = 626.25 +1373.75 = 2000

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Unit 3, Lesson 7

aksik [14]

Answer:

Find the complete table in attached file.

Step-by-step explanation:

Find the Incomplete table in attached file

Given:

A car travels 55 miles per hour for 2 hours.

So the speed of the car 55 miles per hour is constant for 2 hours.

Using speed formula.

$Speed=\frac{distance}{time}$

Second row.

From the second row of the table $time = \frac{1}{2}=0.5\ sec$ and speed is constant $speed = 55\ mi/hr$ , so we need to find only distance.

$Speed=\frac{distance}{time}$

$55=\frac{distance}{0.5}$

$distance = 55\times 0.5$

$distance = 27.5\ mi$

Third row.

From the third row of the table $time =1\frac{1}{2}=\frac{3}{2} = 1.5\ sec$ and speed is constant $speed = 55\ mi/hr$ , so we need to find only distance.

$Speed=\frac{distance}{time}$

$55=\frac{distance}{1.5}$

$distance = 55\times 1.5$

$distance = 82.5\ mi$

Fourth row.

From the fourth row of the table $distance =110\ miles$ and speed is constant $speed = 55\ mi/hr$ , so we need to find time.

$Speed=\frac{distance}{time}$

$time=\frac{distance}{speed}$

$time=\frac{110}{55}$

$time = 2\ sec$

Therefore we complete the table from the above calculation.

8 0

3 years ago

Complete the square and write in standard form. Show all work.What would be the conic section:CircleEllipseHyperbolaParabola

mote1985 [20]

ANSWER

This is an ellipse. The equation is:

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

EXPLANATION

We have to complete the square for each variable. To do so, we have to take the first two terms and compare them with the perfect binomial squared formula,

$(a+b)^2=a^2+2ab+b^2$

For x we have to take 16x² and -32x. Since the coefficient of x is not 1, first, we have to factor out the coefficient 16,

$16x^2-32x=16(x^2-2x)$

Now, the first term of the expanded binomial would be x and the second term -2x. Thus, the binomial is,

$(x-1)^2=x^2-2x+1$

To maintain the equation, we have to subtract 1,

$16(x^2-2x+1-1)=16((x-1)^2-1)=16(x-1)^2-16$

Now, we replace (16x² - 32x) from the given equation by this equivalent expression,

$16(x-1)^2-16+9y^2+72y+16=0$

The next step is to do the same for y. We have the terms 9y² + 72y. Again, since the coefficient of y² is not 1, we factor out the coefficient 9,

$9y^2+72y=9(y^2+8y)$

Following the same reasoning as before, we have that the perfect binomial squared is,

$(y+4)^2=y^2+8y+16$

Remember to subtract the independent term to maintain the equation,

$9(y^2+8y)=9(y^2+8y+16-16)=9((y+4)^2-16)=9(y+4)^2-144$

And now, as we did for x, replace the two terms (9y² + 72y) with this equivalent expression in the equation,

$16(x-1)^2-16+9(y+4)^2-144+16=0$

Add like terms,

$\begin{gathered} 16(x-1)^2+9(y+4)^2+(-16-144+16)=0 \\ 16(x-1)^2+9(y+4)^2-144=0 \end{gathered}$

Add 144 to both sides,

$\begin{gathered} 16(x-1)^2+9(y+4)^2-144+144=0+144 \\ 16(x-1)^2+9(y+4)^2=144 \end{gathered}$

As we can see, this is the equation of an ellipse. Its standard form is,

$\frac{(x-h)^2}{a^2}+\frac{(y-k)^2}{b^2}=1$

So the next step is to divide both sides by 144 and also write the coefficients as fractions in the denominator,

$\begin{gathered} \frac{16(x-1)^2}{144}+\frac{9(y+4)^2}{144}=\frac{144}{144} \\ \\ \frac{(x-1)^2}{\frac{144}{16}}+\frac{(y+4)^2}{\frac{144}{9}}=1 \end{gathered}$

Finally, we have to write the denominators as perfect squares, so we identify the values of a and b. 144 is 12², 16 is 4² and 9 is 3²,

$\frac{(x-1)^2}{(\frac{12}{4})^2}+\frac{(y+4)^2}{(\frac{12}{3})^2}=1$

Note that we can simplify a and b,

$\frac{12}{4}=3\text{ and }\frac{12}{3}=4$

Hence, the equation of the ellipse is,

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

3 0

1 year ago

Who spent more of their allowed on pizza? 2/5 and 0.25

zheka24 [161]

Answer:

2/5, because 2/5 is bigger than 0.25.

Step-by-step explanation:

5 0

3 years ago

Read 2 more answers

Find value of n. 5/16=n/80

Viefleur [7K]

5/16 = n/80
bring 80 over to the other side to leave n alone. 80 then gets a multiplication sign in front of it.
5/16 x 80=n
5/16=0.3125
0.3125x80=25
n=25
hope this helps

3 0

2 years ago

What is half of a ton???

leva [86]

Answer:1000

Step-by-step explanation:

1 ton is 2000 pounds

Take 2000 divide in half

7 0

3 years ago