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3 years ago

13

5. If x + x-1 = a, express x2 + 2 + x-2 in terms of a.

1 answer:

yawa3891 [41]3 years ago

3 0

I suppose the question is, if $x+x^{-1}=a$ , what is $x^2+2+x^{-2}$ ?

Recall that $(a+b)^2=a^2+2ab+b^2$ . It follows that for $x\neq0$ ,

$x^2+2+x^{-2}=x^2+2xx^{-1}+(x^{-1})^2=(x+x^{-1})^2=\boxed{a^2}$

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2. What is the sum of two numbers that are additive inverses?

Stells [14]

Answer:

what are the choices

Step-by-step explanation:

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3 years ago

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I will give brainliest to whoever can answer this question. It’s due in 40 min Please help me )):

Aleonysh [2.5K]

Given:

$m\angle L=m\angle Z=70^\circ$

$m\angle N=m\angle Y=90^\circ$

To find:

The value of $m\angle 1$ .

Solution:

In triangle XYZ,

$m\angle Y=m\angle N=90^\circ$ (Given)

$m\angle Z=m\angle L=70^\circ$ (Given)

$m\angle X+m\angle Y+m\angle Z=180^\circ$ [Angle sum property]

$m\angle 1+90^\circ+70^\circ=180^\circ$

$m\angle 1+160^\circ=180^\circ$

$m\angle 1=180^\circ-160^\circ$

$m\angle 1=20^\circ$

Therefore, the $m\angle 1$ is 20°.

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3 years ago

What does this problem equal?show your work.<br><br>-12(k+4)=60

HACTEHA [7]

Hey there!

First, divide both sides by 12
-12(k+4)/-12= 60/-12 and you would getk+4=5
Now subtract 4 from both sides

k+4-4= 5-4

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3 years ago

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3 years ago

The midpoint of segment AB is (4, 2). The coordinates of point A are (2, 7). Find the coordinates of point B.

erastovalidia [21]

Answer:

<h3>The option B) is correct</h3><h3>Therefore the coordinate of B $(x_2,y_2)$ is (6,-3)</h3>

Step-by-step explanation:

Given that the midpoint of segment AB is (4, 2). The coordinates of point A is (2, 7).

<h3>To Find the coordinates of point B:</h3>

Let the coordinate of A be $(x_1,y_1)$ is (2,7) respectively
Let the coordinate of B be $(x_2,y_2)$
And Let M(x,y) be the mid point of line segment AB is (4,2) respectively
The mid-point formula is

<h3> $M(x,y)=(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2})$ </h3>

Now substitute the coordinates int he above formula we get
$(4,2)=(\frac{2+x_2}{2},\frac{7+y_2}{2})$
Now equating we get

$4=\frac{2+x_2}{2}$ $2=\frac{7+y_2}{2}$

Multiply by 2 we get Multiply by 2 we get

$4(2)=2+x_2$ $2(2)=7+y_2$

$8=2+x_2$ $4=7+y_2$

Subtracting 2 on both

the sides Subtracting 7 on both the sides

$8-2=2+x_2-2$ $4-7=7+y_2-7$

$6=x_2$ $-3=y_2$

Rewritting the above equation Rewritting the equation

$x_2=6$ $y_2=-3$

<h3>Therefore the coordinate of B $(x_2,y_2)$ is (6,-3)</h3><h3>Therefore the option B) is correct.</h3>

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3 years ago