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3 years ago

SoIve the system of equations by elimination. (Addition) 1)-2x + 4y = -22 2x + 8y = –26

Mathematics

2 answers:

Morgarella [4.7K]3 years ago

8 0

Answer:

(3, - 4 )

Step-by-step explanation:

Given the 2 equations

- 2x + 4y = - 22 → (1)

2x + 8y = - 26 → (2)

Adding the 2 equations term by term will eliminate the x- term, that is

12y = - 48 ( divide both sides by 12 )

y = - 4

Substitute y = - 4 into either of the 2 equations and solve for x

Substituting into (2)

2x + 8(- 4) = - 26

2x - 32 = - 26 ( add 32 to both sides )

2x = 6 ( divide both sides by 2 )

x = 3

solution is (3, - 4 )

Rufina [12.5K]3 years ago

6 0

Answee:

We have these two equations:

-2x +4y =-22

2x + 8y -26

We need to try to get the same number multiplying both x or y, I think we can make the 2 of the first equation negative, for that, we multiply all the equation by -1:

2x + 8y =-26 ---- -2x - 8y =26

Now we have this:

-2x +4y = -22

-2x -8y = 26

Now e substract both equations:

-2x - (-2x) +4y -(-8y) = -22-26

12y = -48

Y = -48/12 = -4

And we replace to get x

-2x + 4y = -22

-2x +4*(-4)=-22

-2x - 16 = -22

x= -6/-2 =3

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skelet666 [1.2K]

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A0.15

Step-by-step explanation:

7 0

3 years ago

2 sin^2 (x) -5 sin (x) -3=0

andreyandreev [35.5K]

we have that

$2sin^{2} x-5sin x-3=0$

I. Rewrite the equation by substituting the expression u in for sin x.

$2u^{2} -5u-3=0$

II. Factor the quadratic expression. Rewrite the equation with factors instead of the original polynomial.

$2u^{2} -5u-3=0$ is equal to

using a graph calculator-----> see the attached figure

$(u-3)*(2u+1)=0$

III. Use the zero product property to solve the quadratic equation.

$(u-3)*(2u+1)=0$

(u-3)=0--------------> u=3

(2u+1)=0-------- 2u=-1------> u=-1/2-----> u=-0.5

IV. Rewrite your solutions to Part III by replacing u with sin x.

sin x=3--------> is not the solution (sin x can not be greater than 1)

sin x=-0.50------>is the solution

V. Solve the remaining equations for x, giving all solutions to the equation.

sin x=-0.50

if the sine is negative

then

x belong to the III or IV quadrant

we know that

sin 30°=0.50

the solution for the III quadrant is

x=180°+30°-------> x=210°

the solution for the IV quadrant is

x=360°-30°------> x=330°

5 0

3 years ago

The floor plan shows an l shaped room. Shane wants to buy carpet for the room. The cost for one square foot of carpet is $4. Wha

VashaNatasha [74]

The area of shape is the amount of space on it.

The cost to carpet the room is $224

From the floor plan (see attachment), we can divide the room into two shapes:

A 8ft by 6ft rectangle
A 4ft by 2ft rectangle

So, the area of the floor plan is:

$\mathbf{Area = 8ft \times 6ft + 4ft \times 2ft}$

$\mathbf{Area = 48ft^2 + 8ft^2}$

$\mathbf{Area = 56ft^2}$

The unit cost of carpet is $4 per one square foot

So, the cost to carpet the room is:

$\mathbf{Cost = \$4 \times 56}$

$\mathbf{Cost = \$224}$

Hence, the cost to carpet the room is $224