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3 years ago

Which equals the product of (x – 3)(2x + 1)

Mathematics

2 answers:

vodka [1.7K]3 years ago

7 0

Answer:

$2 {x}^{2} - 5x - 3$

Step-by-step explanation:

$( x - 3)(2x + 1) \\ = x(2x + 1) - 3(2x + 1) \\ = 2 {x}^{2} + x - 6x - 3 \\ = 2 {x}^{2} - 5x - 3$

alekssr [168]3 years ago

6 0

Answer:

Step-by-step explanation:

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A point is chosen randomly on AD. What is the probability that the point is on BC?

Nadusha1986 [10]

I’m pretty sure it’s b but idk 100% sorry if it’s wrong

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3 years ago

Please help me for the love of God if i fail I have to repeat the class

Elena-2011 [213]

$\theta$ is in quadrant I, so $\cos\theta>0$ .

$x$ is in quadrant II, so $\sin x>0$ .

Recall that for any angle $\alpha$ ,

$\sin^2\alpha+\cos^2\alpha=1$

Then with the conditions determined above, we get

$\cos\theta=\sqrt{1-\left(\dfrac45\right)^2}=\dfrac35$

and

$\sin x=\sqrt{1-\left(-\dfrac5{13}\right)^2}=\dfrac{12}{13}$

Now recall the compound angle formulas:

$\sin(\alpha\pm\beta)=\sin\alpha\cos\beta\pm\cos\alpha\sin\beta$

$\cos(\alpha\pm\beta)=\cos\alpha\cos\beta\mp\sin\alpha\sin\beta$

$\sin2\alpha=2\sin\alpha\cos\alpha$

$\cos2\alpha=\cos^2\alpha-\sin^2\alpha$

as well as the definition of tangent:

$\tan\alpha=\dfrac{\sin\alpha}{\cos\alpha}$

Then

1. $\sin(\theta+x)=\sin\theta\cos x+\cos\theta\sin x=\dfrac{16}{65}$

2. $\cos(\theta-x)=\cos\theta\cos x+\sin\theta\sin x=\dfrac{33}{65}$

3. $\tan(\theta+x)=\dfrac{\sin(\theta+x)}{\cos(\theta+x)}=-\dfrac{16}{63}$

4. $\sin2\theta=2\sin\theta\cos\theta=\dfrac{24}{25}$

5. $\cos2x=\cos^2x-\sin^2x=-\dfrac{119}{169}$

6. $\tan2\theta=\dfrac{\sin2\theta}{\cos2\theta}=-\dfrac{24}7$

7. A bit more work required here. Recall the half-angle identities:

$\cos^2\dfrac\alpha2=\dfrac{1+\cos\alpha}2$

$\sin^2\dfrac\alpha2=\dfrac{1-\cos\alpha}2$

$\implies\tan^2\dfrac\alpha2=\dfrac{1-\cos\alpha}{1+\cos\alpha}$

Because $x$ is in quadrant II, we know that $\dfrac x2$ is in quadrant I. Specifically, we know $\dfrac\pi2$ , so $\dfrac\pi4$ . In this quadrant, we have $\tan\dfrac x2>0$ , so

$\tan\dfrac x2=\sqrt{\dfrac{1-\cos x}{1+\cos x}}=\dfrac32$

8. $\sin3\theta=\sin(\theta+2\theta)=\dfrac{44}{125}$

6 0

3 years ago

Given: Q = 7m + 3n, R = 11 - 2m, S = n + 5, and T = -m - 3n + 8.

murzikaleks [220]

Answer:

The answer is 10m + 7n - 14

Step-by-step explanation:

Q = 7m + 3n

R = 11 - 2m

S = n + 5

T = -m - 3n + 8

[Q - R] + [S - T] is

[ 7m + 3n - (11 - 2m) ] + [ n + 5 - ( - m - 3n+8)]

Solve the terms in the bracket first

That's

( 7m + 3n - 11 + 2m ) + ( n + 5 + m + 3n - 8)

( 9m + 3n - 11 ) + ( m + 4n - 3)

<u>Remove the brackets</u>

That's

9m + 3n - 11 + m + 4n - 3

<u>Group like terms</u>

9m + m + 3n + 4n - 11 - 3

The final answer is

Hope this helps you

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3 years ago

Find the source area of the space figure represented by the net

sergejj [24]

I assume you meant "surface area" :)

Looking at the net, it looks like if you folded it back together it would form to become a triangular prism.

To calculate the surface area of a triangular prism, you would use the formula: A = bh + 2ls + lb, where b is the base of the triangular faces, h is the height of the prism, l is the length of the prism, and s is the side length of the prism.

I attached a picture to help you see what these labels are.

Looking at the diagram you've provided, we can assume that b = 7 cm, h = 4 cm, l = 8 cm, and s = 5 cm. Substitute these into the formula.

A = bh + 2ls + lb ==> A = (7)(4) + 2(8)(5) + (8)(7)

Multiply from left to right.

28 + 80 + 56

Add.

164

The surface area of this triangular prism is A) 164 cm^2.

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3 years ago

X+3/12=2/7 plz <br> show work

Pachacha [2.7K]

35714286/1000000000, simplified is <span>17857143/500000000.</span>

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3 years ago