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denpristay [2]
3 years ago
13

The polynomial x^2-18x+81 represents the area(in square feet) of a square courtyard. Write an expression for the perimeter of th

e courtyard.
Mathematics
1 answer:
vovangra [49]3 years ago
7 0

Answer:

4x - 36 feet

Step-by-step explanation:

The area A of a  square whose sides are s units is given as

A = s * s

Given that the area A = x^2-18x+81, factorizing

A = x^2-9x-9x+81

A= x(x-9)-9(x-9)

A = (x-9)(x-9)

A = (x-9)^2

This means that the size of each side of the square  courtyard is x-9 feet long

Recall that the perimeter P of a square whose side is s long is given as

P = 4s hence since the side of the courtyard is x - 9 feet, the perimeter of the courtyard

P = 4(x-9)

= 4x - 36 feet

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The equation y 10x describes the amount of money Sandra earns, where x is the number of hours she
tester [92]

Answer:

a) $10 per hour

b) Sandra

Step-by-step explanation:

<u>Complete Question:</u>

<em>The equation y 10x describes the amount of money Sandra earns, where x is the number of hours she  works and y is the amount of money she earns </em>

<em>The table shows the amount of money Susan cams for different numbers of hours worked</em>

<em>Susan's Earnings </em>

<em>Time (h)           Money Earned</em>

<em>5                              40</em>

<em>8                              64                </em>

<em>10                             80</em>

<em>(a) How much money does Sandra eam per hour? Show your work </em>

<em>(b) Who earns more per hour? Justify your answer</em>

<em />

<em />

<u>Answer:</u>

a)

y = 10x is sandra's equation. To find her hourly rate, we need to find how much she earns in "1" hour. Since x is hours, we plug in x = 1 and find y (which is her pay).

y = 10x

y = 10(1)

y = 10

$10 is Sandra's hourly rate.

b)

To find who earns more per hour, we need to find the hourly rate of Susan as well from the table. Then compare.

5 hours = $40 so per hour is 40/5 = 8

8 hours is 64, so per hour 64/8 = 8

10 hours is 80, so 80/10 = 8

The table is justified at $8 per hour.

We know Sandra earns $10/hr and Susan earns $8 per hour. So Sandra earns more per hour.

4 0
2 years ago
Add and express your answer in scientific notation (5.7 x 10^8) +(3.2 x 10^6)
kaheart [24]

5.7+3.2=8.9

10^8+10^6=10^14

(8.9+10^14)

---

hope it helps

3 0
2 years ago
2. Name the numerator and the denominator in each fraction.
marishachu [46]

Answer:

Step-by-step explanation:

a.11/12 =11 is numerator and 12 is denominator

b.7/512 =75 is numerator and 512 is denominator

c.12/10 = 12 is numerator and 10 is denominator

d0/78 = 0 is numerator and 78 is denominator

point to remember : In fraction,upper part is always numerator and down part is denominator.

6 0
2 years ago
Express 15.68 trillion in scientific notation.
hram777 [196]

Answer: one billion 1,000,000,000 1 x 109

ten billion 10,000,000,000 1 x 1010

one hundred billion 100,000,000,000 1 x 1011

one trillion 1,000,000,000,000 1 x 1012

Step-by-step explanation:

So sorry if this did not help!

5 0
3 years ago
Please help, I really need this
Nady [450]

9514 1404 393

Answer:

  (a) -- the correct choice is highlighted

Step-by-step explanation:

The units of specific heat tell you what quantities make up the ratio.

  \dfrac{390\text{ J}}{1\text{ kg$\cdot^\circ$C}}=\dfrac{-12.0\text{ J}}{0.012\text{ kg}\cdot\Delta T}\\\\\Delta T=\dfrac{-12.0}{0.012\cdot390}\ ^\circ\text{C}\approx-2.56\text{ $^\circ$C}

The temperature will decrease by 2.56 C.

4 0
2 years ago
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