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2 years ago

14

X+y=13and x-y=2 what is the value of x^2-y^2

2 answers:

Inessa [10]2 years ago

7 0

Just a quick sidenote.

$\bf \textit{difference of squares}
\\ \quad \\
(a-b)(a+b) = a^2-b^2\qquad \qquad 
a^2-b^2 = (a-b)(a+b)\\\\
-------------------------------\\\\
x+y=13\qquad x-y=2
\\\\\\
x^2-y^2\implies (x+y)(x-y)\implies (13)(2)$

Kazeer [188]2 years ago

3 0

X+y=13
x-y=2

Add the equations (elimination method)

x+y+x-y=13+2
2x=15
x=7.5

Plug in this y value

7.5-y=2
-y=-5.5
y=5.5

Plug in both the x and y values into the equation asked for

(7.5)^2-(5.5)^2
56.25-30.25

Final answer: 26

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The area of a square carpet tile is 900 square centimeters. What is the length of one edge of the tile in centimeters

satela [25.4K]

Let the side of one edge of tile = a cm.

So area of tile = (side)^2 = $a^2$

But area of tiles = 900 square centimeter.

So $a^2 = 900$

$a = \sqrt{900}$
$= 30$

So side of one edge of tile is = 30 cm

8 0

3 years ago

Jayden and Sheridan both tried to find the missing side of the right triangle. A right triangle is shown. One leg is labeled as

stellarik [79]

Answer:

Sheridan's Work is correct

Step-by-step explanation:

we know that

The lengths side of a right triangle must satisfy the Pythagoras Theorem

$c^{2}=a^{2}+b^{2}$

where

a and b are the legs

c is the hypotenuse (the greater side)

In this problem

Let

$a=7\ cm\\c=13\ cm$

substitute

$13^{2}=7^{2}+b^{2}$

Solve for b

$169=49+b^{2}$

$b^{2}=169-49$

$b^{2}=120$

$b=\sqrt{120}\ cm$

$b=10.95\ cm$

we have that

<em>Jayden's Work</em>

$a^{2}+b^{2}=c^{2}$

$a=7\ cm\\b=13\ cm$

substitute and solve for c

$7^{2}+13^{2}=c^{2}$

$49+169=c^{2}$

$218=c^{2}$

$c=\sqrt{218}\ cm$

$c=14.76\ cm$

Jayden's Work is incorrect, because the missing side is not the hypotenuse of the right triangle

<em>Sheridan's Work</em>

$a^{2}+b^{2}=c^{2}$

$a=7\ cm\\c=13\ cm$

substitute

$7^{2}+b^{2}=13^{2}$

Solve for b

$49+b^{2}=169$

$b^{2}=169-49$

$b^{2}=120$

$b=\sqrt{120}\ cm$

$b=10.95\ cm$

therefore

Sheridan's Work is correct

6 0

3 years ago

Read 2 more answers

In a 50-gram portion of cereal, 8 grams of it are sugar . Which of the following represents the percent of the 50-grams that is

Mars2501 [29]

Answer:

3) 16

8 is 16% of 50

8 0

3 years ago

The rectangular rug in Marcia's living room measures 12 feet by 109 inches. What is the rug's area in square feet?

Marrrta [24]

Answer:

109 square feet.

Step-by-step explanation:

109 in: = 109/12 = 9.0833333.... = 9 5/60 = (540+5)/60 = 545/60

Area = L*w

L = 545/60 feet

W = 12 feet

Area = 545/60 * 12

Area = 545*12/60

Area = 545 /5 = 109 square feet.

3 0

3 years ago

Blake and Ned work for a home remodeling business. They are putting the final touches on a home they renovated. Working alone, B

gizmo_the_mogwai [7]

Answer: The time taken by both of them if they work together is given by

$3\dfrac{3}{5}\ hours$

Step-by-step explanation:

Since we have given that

Time taken by Blake to paint one room = 9 hours

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Work done by Blake = $\dfrac{1}{9}$

Work done by Ned = $\dfrac{1}{6}$

Total work done by both of them together is given by

$\dfrac{1}{6}+\dfrac{1}{6}\\\\=\dfrac{3+2}{18}\\\\=\dfrac{5}{18}$

So, the time taken by both of them if they work together is given by

$\dfrac{18}{5}=3\dfrac{3}{5}\ hours$

7 0

3 years ago

Read 2 more answers