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3 years ago

Can someone explain how to do this please?

Mathematics

1 answer:

Jobisdone [24]3 years ago

4 0

$\bf \begin{cases} \boxed{y}=-2x\\\\ -x-y=4 \end{cases} \\\\[-0.35em] ~\dotfill\\\\ \stackrel{\textit{since we know what \boxed{y} is, let's substitute it in the 2nd equation}}{-x-\left( \boxed{-2x} \right)=4\implies -x+2x=4\implies x=4} \\\\[-0.35em] ~\dotfill\\\\ y=-2x\implies y=-2(4)\implies y=-8 \\\\[-0.35em] \rule{34em}{0.25pt}\\\\ ~\hfill (4,-8)~\hfill$

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Can someone please help

ruslelena [56]

You can find the answer by substituting the x-values provided in the question and seeing if you get what the question says.

a satisfies all of the parameters.
b doesn’t satisfy g(-1), so it’s not b.
c doesn’t satisfy g(-1), so it’s not c.
d doesn’t satisfy g(-1), so it’s not d.

The correct answer is a.

6 0

3 years ago

Factor the trinomial 2x^2+15x+7

Mashutka [201]

Answer:

(2x+1)(x+7)

Step-by-step explanation:

2x2+15x+7

For a polynomial of the form ax2+bx+c

, rewrite the middle term as a sum of two terms whose product is a⋅c=2⋅7=14 and whose sum is b=15

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2x2+x+14x+7

Factor out the greatest common factor from each group.

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x(2x+1)+7(2x+1)

Factor the polynomial by factoring out the greatest common factor, 2x+1

(2x+1)(x+7)

3 0

2 years ago

Find the value of sin(a/2) if cosa= 12/13<br>

daser333 [38]

Answer: sin $\frac{a}{2}$ = ± $\frac{1}{\sqrt{26} }$

Step-by-step explanation:

We very well know that,

cos2A=1−2sin²A

⟹ sinA = ± $\sqrt{(1-} \frac{cos2A}{2} )$

As required, set A = $\frac{a}{2}$ & cos a= $\frac{12}{13}$ ,thus we get

sin $\frac{a}{2}$ =± $\sqrt{\frac{1-cos a}{2} }$

∴ sin $\frac{a}{2}$ =± $\sqrt{\frac{1-\frac{12}{13} }{2} }$ = ± $\frac{1}{\sqrt{26} }$

since ,360° < $\frac{a}{2}$ <450°

,180° < $\frac{a}{2}$ <225°

Now, we are to select the value with the correct sign. It's is obvious from the above constraints that the angle a/2 lies in the III-quadrant where 'sine' has negative value, thus the required value is negative.

hope it helped!

5 0

2 years ago

Use the graph to answer the question.

Law Incorporation [45]

Answer:

Its A.

Step-by-step explanation:

Edge 2021

4 0

3 years ago

Read 2 more answers