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zloy xaker [14]

3 years ago

10

Evaluate the expression when m=-6. 2 m + 5m - 4

1 answer:

Brums [2.3K]3 years ago

5 0

Answer:

2

Step-by-step explanation:

m^2 + 5m - 4

Let m = -6

( -6) ^2 + 5(-6) -4

Exponents first

36 + 5(-6) -4

Then multiply

36 -30 -4

Then subtract

6 -4

2

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The equation of line WX is 2x + y = -5. What is the equation of a line perpendicular to line WX in slope-intercept form that con

sveticcg [70]

Answer:

The third choice is the one you want

Step-by-step explanation:

If we are to write the equation of a line perpendicular to WX, we first must determine what the slope of the WX is, because the line perpendicular to WX has a slope that is the flip of the slope of WX with the opposite sign. Solving for y takes care of finding the slope of WX:

2x + y = -5 so

y = -2x - 5

The slope is -2. That means that the reciprocal slope is 1/2. Using that slope along with the coordinates x = -1 and y = -2, we first write the line using point-slope form and then solve it for y. Start by filling in the m, the x value and the y value:

$y - (-2) = \frac{1}{2}(x-(-1))$

Getting rid of the double negatives gives us:

$y+2=\frac{1}{2}(x+1)$

Distributing then gives us:

$y+2=\frac{1}{2}x+\frac{1}{2}$

And finally solving for y (I am going to express the 2 on the left as 4/2 when I move it by subtraction in order to add those fractions):

$y=\frac{1}{2}x+\frac{1}{2}-\frac{4}{2}$

And the final equation in slope-intercept form is:

$y=\frac{1}{2}x-\frac{3}{2}$

8 0

3 years ago

Rewrite with only sin x and cos x.

Annette [7]

Option A

$\cos 3 x=\cos x-4 \cos x \sin ^{2} x$

<em><u>Solution:</u></em>

Given that we have to rewrite with only sin x and cos x

Given is cos 3x

$cos 3x = cos(x + 2x)$

We know that,

$\cos (a+b)=\cos a \cos b-\sin a \sin b$

Therefore,

$\cos (x+2 x)=\cos x \cos 2 x-\sin x \sin 2 x$ ---- eqn 1

We know that,

$\sin 2 x=2 \sin x \cos x$

$\cos 2 x=\cos ^{2} x-\sin ^{2} x$

Substituting these values in eqn 1

$\cos (x+2 x)=\cos x\left(\cos ^{2} x-\sin ^{2} x\right)-\sin x(2 \sin x \cos x)$ -------- eqn 2

We know that,

$\cos ^{2} x-\sin ^{2} x=1-2 \sin ^{2} x$

Applying this in above eqn 2, we get

$\cos (x+2 x)=\cos x\left(1-2 \sin ^{2} x\right)-\sin x(2 \sin x \cos x)$

$\begin{aligned}&\cos (x+2 x)=\cos x-2 \sin ^{2} x \cos x-2 \sin ^{2} x \cos x\\\\&\cos (x+2 x)=\cos x-4 \sin ^{2} x \cos x\end{aligned}$

$\cos (x+2 x)=\cos x-4 \cos x \sin ^{2} x$

Therefore,

$\cos 3 x=\cos x-4 \cos x \sin ^{2} x$

Option A is correct

7 0

3 years ago

Please answer correctly !!!!!!!!!! Will mark brainliest !!!!!!!!!!!!

MArishka [77]

Answer:

- 18y = 1

Step-by-step explanation:

Adding the 2 equations term by term on both sides gives

(- 5x + 5x) + (- 9y - 9y) = (3 - 2), that is

0 + (- 18y) = 1

- 18y = 1

7 0

3 years ago

Please need help on this not too sure on this

kifflom [539]

option 3

they are corresponding angles and are congruent

8 0

3 years ago

What is the greatest common factor of 75 and 30

igor_vitrenko [27]

The answer to this question is 15

3 0

4 years ago

Read 2 more answers