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3 years ago

15

Write two expressions to show a number increased by 11. Then, draw models to prove that both expressions represent the same thin

g.

1 answer:

ioda3 years ago

5 0

Answer:

n + 11 and 11 + n

Step-by-step explanation:

Let n be the unknown number,

n is increased by 11,

That is, n + 11

By the commutative property of addition,

The expression would be,

11 + n

For drawing a model that shows n + 11

Take two boxes in which first shows n and second shows 11 and add them,

Similarly, for showing 11 + n, take first box that shows 11 and second box that shows n then add them.

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P(x) = x + 1x² – 34x + 343<br> d(x)= x + 9

Feliz [49]

Answer:

$x=\frac{9}{d-1},\:P=\frac{-297d+378}{\left(d-1\right)^2}+343$

Step-by-step explanation:

Let us start by isolating x for dx = x + 9.

dx - x = x + 9 - x > dx - x = 9.

Factor out the common term of x > x(d - 1) = 9.

Now divide both sides by d - 1 > $\frac{x\left(d-1\right)}{d-1}=\frac{9}{d-1};\quad \:d\ne \:1$ . Go ahead and simplify.

$x=\frac{9}{d-1};\quad \:d\ne \:1$ .

Now, $\mathrm{For\:}P=x+1x^2-34x+343, \mathrm{Subsititute\:}x=\frac{9}{d-1}$ .

$P=\frac{9}{d-1}+1\cdot \left(\frac{9}{d-1}\right)^2-34\cdot \frac{9}{d-1}+343$ .

Group the like terms... $1\cdot \left(\frac{9}{d-1}\right)^2+\frac{9}{d-1}-34\cdot \frac{9}{d-1}+343$ .

$\mathrm{Add\:similar\:elements:}\:\frac{9}{d-1}-34\cdot \frac{9}{d-1}=-33\cdot \frac{9}{d-1}$ > $1\cdot \left(\frac{9}{d-1}\right)^2-33\cdot \frac{9}{d-1}+343$ .

Now for $1\cdot \left(\frac{9}{d-1}\right)^2 > \mathrm{Apply\:exponent\:rule}: \left(\frac{a}{b}\right)^c=\frac{a^c}{b^c} > \frac{9^2}{\left(d-1\right)^2} = 1\cdot \frac{9^2}{\left(d-1\right)^2}$ .

$\mathrm{Multiply:}\:1\cdot \frac{9^2}{\left(d-1\right)^2}=\frac{9^2}{\left(d-1\right)^2}$ .

Now for $33\cdot \frac{9}{d-1} > \mathrm{Multiply\:fractions}: \:a\cdot \frac{b}{c}=\frac{a\:\cdot \:b}{c} > \frac{9\cdot \:33}{d-1} > \frac{297}{d-1}$ .

Thus we then get $\frac{9^2}{\left(d-1\right)^2}-\frac{297}{d-1}+343$ .

Now we want to combine fractions. $\frac{9^2}{\left(d-1\right)^2}-\frac{297}{d-1}$ .

$\mathrm{Compute\:an\:expression\:comprised\:of\:factors\:that\:appear\:either\:in\:}\left(d-1\right)^2\mathrm{\:or\:}d-1 > This\: is \:the\:LCM > \left(d-1\right)^2$

$\mathrm{For}\:\frac{297}{d-1}:\:\mathrm{multiply\:the\:denominator\:and\:numerator\:by\:}\:d-1 > \frac{297}{d-1}=\frac{297\left(d-1\right)}{\left(d-1\right)\left(d-1\right)}=\frac{297\left(d-1\right)}{\left(d-1\right)^2}$

$\frac{9^2}{\left(d-1\right)^2}-\frac{297\left(d-1\right)}{\left(d-1\right)^2} > \mathrm{Since\:the\:denominators\:are\:equal,\:combine\:the\:fractions}> \frac{a}{c}\pm \frac{b}{c}=\frac{a\pm \:b}{c}$

$\frac{9^2-297\left(d-1\right)}{\left(d-1\right)^2} > 9^2=81 > \frac{81-297\left(d-1\right)}{\left(d-1\right)^2}$ .

Expand $81-297\left(d-1\right) > -297\left(d-1\right) > \mathrm{Apply\:the\:distributive\:law}: \:a\left(b-c\right)=ab-ac$ .

$-297d-\left(-297\right)\cdot \:1 > \mathrm{Apply\:minus-plus\:rules} > -\left(-a\right)=a > -297d+297\cdot \:1$ .

$\mathrm{Multiply\:the\:numbers:}\:297\cdot \:1=297 > -297d+297 > 81-297d+297 > \mathrm{Add\:the\:numbers:}\:81+297=378 > -297d+378 > \frac{-297d+378}{\left(d-1\right)^2}$

Therefore $P=\frac{-297d+378}{\left(d-1\right)^2}+343$ .

Hope this helps!

5 0

3 years ago

Find the volume of the given prism. Round to the nearest tenth if necessary.

Alisiya [41]

Hello!

To find the volume of a rectangular prism you do hwl

h is height
w is width
l is length

4.2 * 5.3 * 12.1 = 269.346

The answer is 269.3 cubic centimeters

Hope this helps!

6 0

3 years ago

Plz help me with Q:13 And Q:14

PolarNik [594]

For question 13, you need to look at all the numbers that are less than 1/2 and then count the number of marks in total .
Answer: 7 B
For question 14, you need to first make an equation that suits the circumstances and the situations in this problem.
$25+$24x=$193
$24x=$168
x=7 weeks
x stands for the number of weeks that she has to wait for in order to save enough money to purchase the camera.
Answer: 7 weeks A

5 0

3 years ago

Read 2 more answers

The ratio of the geometric mean and arithmetic mean of two numbers is 3:5, find the ratio of the smaller number to the larger nu

IgorC [24]

Answer:

$\frac{1}{9}$

Step-by-step explanation:

Let the numbers be x,y, where x>y

The geometric mean is

$\sqrt{xy}$

The Arithmetic mean is

$\frac{x + y}{2}$

The ratio of the geometric mean and arithmetic mean of two numbers is 3:5.

$\frac{ \sqrt{xy} }{ \frac{x + y}{2} } = \frac{3}{5}$

We can write the equation;

$\sqrt{xy} = 3$

or

$xy = 9 - - - (2)$

l

and

$\frac{x + y}{2} = 5$

or

$x + y = 10 - - - (2)$

Make y the subject in equation 2

$y = 10 - x - - - (3)$

Put equation 3 in 1

$x(10 - x) = 9$

$10x - {x}^{2} = 9$

${x}^{2} - 10x + 9 = 0$

$(x - 9)(x - 1) = 0$

$x =1 \: or \: 9$

When x=1, y=10-1=9

When x=9, y=10-9=1

Therefore x=9, and y=1

The ratio of the smaller number to the larger number is

$\frac{1}{9}$

3 0

2 years ago

I need help or I will faill this

kari74 [83]

Answer:

-4x2 + 3x - 225

———————————————

3

Step-by-step explanation:

Step 1 :

4

Simplify —

3

Equation at the end of step 1 :

4

(x - (— • x2)) - 75

3

Step 2 :

Equation at the end of step 2 :

4x2

(x - ———) - 75

3

Step 3 :

Rewriting the whole as an Equivalent Fraction :

3.1 Subtracting a fraction from a whole

Rewrite the whole as a fraction using 3 as the denominator :

x x • 3

x = — = —————

1 3

Equivalent fraction : The fraction thus generated looks different but has the same value as the whole

Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator

Adding fractions that have a common denominator :

3.2 Adding up the two equivalent fractions

Add the two equivalent fractions which now have a common denominator

Combine the numerators together, put the sum or difference over the common denominator then reduce to lowest terms if possible:

x • 3 - (4x2) 3x - 4x2

————————————— = ————————

3 3

Equation at the end of step 3 :

(3x - 4x2)

—————————— - 75

3

Step 4 :

Rewriting the whole as an Equivalent Fraction :

4.1 Subtracting a whole from a fraction

Rewrite the whole as a fraction using 3 as the denominator :

75 75 • 3

75 = —— = ——————

1 3

Step 5 :

Pulling out like terms :

5.1 Pull out like factors :

3x - 4x2 = -x • (4x - 3)

Adding fractions that have a common denominator :

5.2 Adding up the two equivalent fractions

-x • (4x-3) - (75 • 3) -4x2 + 3x - 225

—————————————————————— = ———————————————

3 3

Step 6 :

Pulling out like terms :

6.1 Pull out like factors :

-4x2 + 3x - 225 = -1 • (4x2 - 3x + 225)

Trying to factor by splitting the middle term

6.2 Factoring 4x2 - 3x + 225

The first term is, 4x2 its coefficient is 4 .

The middle term is, -3x its coefficient is -3 .

The last term, "the constant", is +225

Step-1 : Multiply the coefficient of the first term by the constant 4 • 225 = 900

Step-2 : Find two factors of 900 whose sum equals the coefficient of the middle term, which is -3 .

-900 + -1 = -901

-450 + -2 = -452

-300 + -3 = -303

-225 + -4 = -229

-180 + -5 = -185

-150 + -6 = -156

For tidiness, printing of 48 lines which failed to find two such factors, was suppressed

Observation : No two such factors can be found !!

Conclusion : Trinomial can not be factored

Final result :

-4x2 + 3x - 225

———————————————

3

7 0

2 years ago