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3 years ago

Solve using elimination x+2y=4 -x-y=2

Mathematics

2 answers:

insens350 [35]3 years ago

8 0

Answer:

x=-8 y=6

Step-by-step explanation:

Add the two equations together. This cancels the x and gets us y=6

Then substitute y in more the first equation which gets us -8

lianna [129]3 years ago

6 0

Answer: y = 6 x = -8

Step-by-step explanation:

X+2Y=4

-X-Y=2

(Combine like terms)

Y= 6

(Plug in 6 for y)

X+2(6)=4

X+12=4

X= -8

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Solve the oblique triangle where side a has length 10 cm, side c has length 12 cm, and angle beta has measure thirty degrees. Ro

strojnjashka [21]

Answer:

The missing side is $B = 6.0\ cm$

The missing angles are $\alpha = 56.2$ and $\theta = 93.8$

Step-by-step explanation:

Given

$A = 10\ cm$

$C = 12\ cm$

$\beta = 30$

The implication of this question is to solve for the missing side and the two missing angles

Represent

Angle A with $\alpha$

Angle B with $\beta$

Angle C with $\theta$

Calculating B

This will be calculated using cosine formula as thus;

$B^2 = A^2 + C^2 - 2ACCos\beta$

Substitute values for A, C and $\beta$

$B^2 = 10^2 + 12^2 - 2 * 10 * 12 * Cos30$

$B^2 = 100 + 144 - 240 * 0.8660$

$B^2 = 100 + 144 - 207.8$

$B^2 = 36.2$

Take Square root of both sides

$B = \sqrt{36.2}$

$B = 6.0$ (Approximated)

Calculating $\alpha$

This will be calculated using cosine formula as thus;

$A^2 = B^2 + C^2 - 2BCCos\alpha$

Substitute values for A, B and C

$A^2 = B^2 + C^2 - 2BCCos\alpha$

$10^2 = 6^2 + 12^2 - 2 * 6 * 12 * Cos\alpha$

$100 = 36 + 144 - 144Cos\alpha$

Collect Like Terms

$100 - 36 - 144 = -144Cos\alpha$

$-80 = -144Cos\alpha$

Divide both sides by -144

$\frac{-80}{-144} = Cos\alpha$

$0.5556 = Cos\alpha$

$\alpha = cos^{-1}(0.5556)$

$\alpha = 56.2$ (Approximated)

Calculating $\theta$

This will be calculated using cosine formula as thus;

$C^2 = B^2 + A^2 - 2BACos\theta$

Substitute values for A, B and C

$12^2 = 6^2 + 10^2 - 2 * 6 * 10Cos\theta$

$144 = 36 + 100 - 120Cos\theta$

Collect Like Terms

$144 - 36 - 100 = -120Cos\theta$

$8 = -120Cos\theta$

Divide both sides by -120

$\frac{8}{-120} = Cos\theta$

$-0.0667= Cos\theta$

$\theta = cos^{-1}(-0.0667)$

$\theta = 93.8$ (Approximated)

4 0

4 years ago

Can any one solve it

yarga [219]

I think its d as
300=br
280=dvd&br
But there's 320 ppl so 320-280=40

7 0

3 years ago

Please help me on this math question

Over [174]

Answerye

Step-by-step explanation:

7 0

3 years ago

A set of pulleys is used to lift a piano with a mass of 102 kg. The piano is lifted 3 meters in 1 minutes. How much power is use

agasfer [191]

Answer:

50.031 watts

Step-by-step explanation:

Formula

Power = Force * distance / time

The units are critical

distance = meters

time = seconds

force = newtons = kg * m / s^2

Solution

F = m * a

a = 9.81

m = 102 kg

F = 102 * 9.81 = 1000.62 Newtons

T = minute = 60 sec/min * 1 min

T = 60 seconds

d = 3 meters

Power = 1000.62 * 3 / 60

Power = 50.031

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Marysya12 [62]

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