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Dominik [7]
3 years ago
13

Ax+by=(a-b) , bx - ay =(a+b) simultaneous linear equations using cross multiplication

Mathematics
1 answer:
Molodets [167]3 years ago
6 0

Answer:

x=1\,,\,y=-1

Step-by-step explanation:

Given: ax+by=a-b\,,\,bx-ay=a+b

To solve: the given linear equations

Solution:

Consider the equations:

A_1x+B_1y+C_1=0\\A_2x+B_2y+C_2=0

By method of cross multiplication:

\frac{x}{B_1C_2-B_2C_1}=\frac{y}{C_1A_2-C_2A_1}=\frac{1}{A_1B_2-A_2B_1}

For equations: ax+by=a-b\,,\,bx-ay=a+b

ax+by-(a-b)=0\\bx-ay-(a+b)=0

Take A_1=a\,,\,B_1=b\,,\,C_1=-(a-b)\,,\,A_2=b\,,\,B_2=-a\,,\,C_2=-(a+b)

So,

\frac{x}{-b(a+b)-a(a-b)}=\frac{y}{-b(a-b)+a(a+b)}=\frac{1}{-a^2-b^2}\\\frac{x}{-ab-b^2-a^2+ab}=\frac{y}{-ab+b^2+a^2+ab}=\frac{1}{-(a^2+b^2)}\\\frac{x}{-(a^2+b^2)}=\frac{y}{a^2+b^2}=\frac{1}{-(a^2+b^2)}\\\frac{x}{-(a^2+b^2)}=\frac{1}{-(a^2+b^2)}\,,\,\frac{y}{a^2+b^2}=\frac{1}{-(a^2+b^2)}\\x=1\,,\,y=-1

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Tanya [424]

Answer:

a. Pr(They both have type O)

= Pr(They both have type O)

= 0.35 x 0.45

= 0.1575 = 15.75%

b. Pr( they both have the same blood type)

= Pr( they both have the same blood type)

= 2/8

= 0.25 = 25%

c. Pr( at least one person has type O)

= Pr (at least one person has type O)

= 1 - 0.3575

= 0.6425 = 64.25%

Step-by-step explanation:

a) Data:

                   O       A         B       AB

Chinese   0.35   0.27    0.26     0.12

American 0.45   0.4      0.11       0.04

b) Calculations:

i. Pr(They both have type O)

= Probability of Chinese with O multiplied by Probability of American with O

= 0.35 * 0.45

= 0.1575 = 15.75%

ii. Pr( they both have the same blood type)

= Probability of two out of 8 outcomes

= 2/8

= 0.25 = 25%

iii. Pr( at least one person has type O)

= Probability of (1 – p(none) )

The probability of none = p(none O blood type)

= p(none)

for Chinese = (0.27 + 0.26 + 0.12) * for American ( 0.4 + 0.11 + 0.04)

= 0.65 * 0.55 = 0.3575

Pr (at least one person has type O) = 1 - 0.3575

= 0.6425

4 0
3 years ago
Why can't <img src="https://tex.z-dn.net/?f=x%5E2-5x-1" id="TexFormula1" title="x^2-5x-1" alt="x^2-5x-1" align="absmiddle" class
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Answer:

Step-by-step explanation:

Discussion.

Not directly. But the quadratic formula can do it. But that's not your question.

the factors you get must contain the factors for 1 which are 1 and - 1

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ASHA 777 [7]

The area of the given figure is 576 cm sq.

The perimeter of the given figure is 96 cm.

Step-by-step explanation:

The shape consists of one semicircle and one square which is cut by a semicircle.

<u>To find Area:</u>

Find the area of semicircle= (πr^2)/2

where r is the radius= diameter/2= 24/2= 12 cm

Area of semicircle= π(12)(12)/2= 144π/2= 72π cm sq.

Find the area of square= a^2

where a is the side of square, a=24 cm.

Area of the square= 24*24= 576 cm sq.

To find the total area of the given figure,

Area of the figure= Area of semicircle+(area of square- area of semicircle)

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<u>To find perimeter:</u>

Perimeter of semicircle= (2πr)/2

                                       = (2*12*π)/2= 12π cm

Perimeter of square= 4a =4*24 =96 cm

Perimeter of the given figure=  perimeter of semicircle+(perimeter of                        square- perimeter of semicircle)

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Answer:

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3 years ago
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goblinko [34]

Answer:

Approximately 11.5 units.

Step-by-step explanation:

We need to find the side opposite to ∠W. We are given the two angles ∠W and ∠X. We are also given that Side X is equal to 7. Therefore, we can use the Law of Sines.

Now, like last time, use the Law of Sines:

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We can ignore the first term. Plug in 144 for ∠W, 21 for ∠X, and 7 for <em>x</em>.

\frac{\sin(144)}{w}=\frac{\sin(21)}{7}

Cross multiply:

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6 0
3 years ago
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