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3 years ago

X=-4y 3x+2y=20 Substitution

Mathematics

2 answers:

nadezda [96]3 years ago

7 0

Answer: y= -2; x = 8

Step-by-step explanation:

X=-4y.......equation 1

3x+2y=20......equation 2

Substitute the value of x into equation 2

3 (-4y) + 2y = 20

-12y + 2y = 20

-10y = 20

Divide both sides by -10

y = 20/-10

y = -2

Substitute the value of y into equation 1 to get the value of x

x = - 4(-2)

x = 8

I hope this helps greatly, please mark as brainliest answer.

inysia [295]3 years ago

6 0

Answer:

y=-2

x=8

Step-by-step explanation:

Substitute x=-4y into the other equation:

3(-4y)+2y =20

Multiply out the parenthesis:

-12y +2y = 20

-10y =20

Divide on both sides by -10:

y = 20/-10 =-2

Now, knowing y,you can substite it in the previous equation for x:

x = -4(-2)= 8

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If the area of a triangle is 28in2 and the height is 8 inches, determine the length of the base.

klemol [59]

area of triangle formula = ½ × B × H

28in2 = ½ × B × (8)

28in2 = 4 × B

28 ÷ 4 = B

Therefore, length of base = 7 inches

i hope my solution helps :))

6 0

2 years ago

A cylinder has a volume of 360 cubic centimeters. Find the volume of a cone with the same height and diameter as

harina [27]

Formula for the cylinder = V=πr2h

Formula for the cone = 1/3πr²H

Description:

So if the cone and a cylinder have the same radius and the same height then it will be greater. So plug in these formula.

Formula:

Vcone = 3Vcone

Vcylinder = 360cm³

Vcone = 1/3 360cm³ = 120cm³

Answer: 120cm³

Hope this helps.

4 0

2 years ago

What are the real and complex solutions of the polynomial equation? x^4-41x^2=-400. *work needed*

pickupchik [31]

<h3>Answer: x = -5, -4, 4 and 5.</h3><h3>All four zeros are real solutions.</h3>

Step-by-step explanation:

Given the polynomial equation $x^4-41x^2=-400$ .

Adding 400 on both sides to get rid 400 from right side and set 0 on right side, we get

$x^4-41x^2+400=-400+400$ .

$x^4-41x^2+400=0$ .

Factoring by product sum rule.

We need product of 400 and sum upto -41.

We can see that 400 = -25 × -16 = 400 and -25-16 = -41.

Therefore,

$x^4-25x^2-16x^2+400=0$

Making it into two groups, we get

$(x^4-25x^2)+(-16x^2+400)=0$

Factoring out GCF of each group, we get

$x^2(x^2-25)-16(x^2-25)=0$

$(x^2-25)(x^2-16) =0$

Factoring out $(x^2-25)$ and $(x^2-16)$ separately by difference of the squares identity $a^2-b^2=(a-b)(a+b)$ , we get

$(x^2-25) = x^2-5^2= (x-5)(x+5)$ and

$x^2-16 = x^2-4^2 =(x-4)(x+4)$ .

Therefore,

$(x-5)(x+5)(x-4)(x+4) =0$

Applying zero product rule,

x-5=0

x+5=0

x-4=0 and

x+4=0.

Therefore,

<h3>x = -5, -4, 4 and 5.</h3><h3>All four zeros are real solutions.</h3>

6 0

2 years ago

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kherson [118]

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7 0

2 years ago

PLEAAASE ANSWER TIMER IS RUNNING OUT

lisabon 2012 [21]

Answer:

the correct answer is 1/2.

How i came to this answer was adding all of the number of medals together for all of the years, coming up to a total of 22. When asking about probability of any given set or amount of things, you always take the selected values and take them out of the whole amount. Years 2009 and 2012 have a whole selected value of 11 (4+7). Therefore you're "taking" 11 from 22, coming up with the fraction 11/22 seeing as that is not a answer choice the next step is to simply the fraction to 1/2.

4 0

2 years ago

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