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3 years ago

14.What is the solution of the system?

Mathematics

1 answer:

Archy [21]3 years ago

3 0

Answer:

14. x=-2.5, y = -7

15. x=28 y = -20

Step-by-step explanation:

14. Let's solve this system by elimination. Multiply the first equation by -1.

-1*(4x-y)= -1*(- 3)

-4x +y = 3

Then add this to the second equation.

-4x+y = 3

6x-y= - 8

--------------

2x = -5

Divide each side by 2

x = -2.5

We still need to find y

-4x+y =3

-4(-2.5) + y =3

10 +y =3

Subtract 10 from each side.

y = 3-10

y = -7

15.I will again use elimination to solve this system, because using substitution will give me fractions which are harder to work with. I will elimiate the y variable. Multiply the first equation by 11

11( 5x+6y)= 11*20

55x+66y = 220

Multiply the second equation by -6

-6(9x+11y)=32*(-6)

-54x-66y = -192

Add the modified equations together.

55x+66y = 220

-54x-66y = -192

---------------------------

x = 28

We still need to solve for y

5x+6y = 20

5*28 + 6y =20

140 + 6y = 20

Subtract 140 from each side

6y = -120

Divide by 6

y = -20

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Answer:
764x
Step by step explanation:
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2 years ago

6. A pedestrian underpass is constructed using a cylindrical pipe of radius 2.6 m. The bottom of

Ivanshal [37]

Answer:

4.5 m

Step-by-step explanation:

Distance from center to the the bottom part where headroom begins is 3.9 m-2.6 m=1.3 m

Since the radius is 2.6 m and acts as hypotenuse(see attached image), then the other length will be

$\sqrt {2.6^{2}-1.3^{2}=5.07}=2.25166605
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3 years ago

Find the area of this figure.

ryzh [129]

Answer:

1824 square inches

Step-by-step explanation:

First, separate the figure into two sections. The triangle on top, and the rectangle on the bottom.

to get the area of the triangle, simply multiply height times width and divide by two.

48 x 12 = 576

576/2 = 288

the area of the triangle is 288 sq in

next, multiply the height and width of the rectangle to get its area.

32 x 48 = 1536

add 1536 to 288 to get the area of the complete figure

1536 + 288 = 1824

the answer is 1824 square inches

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3 years ago

Anna is five years old. my age is six years more than thrice her age. how old am i

Hoochie [10]

Answer:

21 years old

Step-by-step explanation:

Anna = 5

You = 6 + (5)3

Equation =

(5)3 + 6

15 + 6 = 21

You are 21

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

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2 years ago

<img src="https://tex.z-dn.net/?f=%20%5Cunderline%7B%20%5Cunderline%7B%20%5Ctext%7BQuestion%7D%7D%7D%20%3A%20" id="TexFormula1"

Lubov Fominskaja [6]

Answer:

See Below.

Step-by-step explanation:

We are given the isosceles triangle ΔABC. By the definition of isosceles triangles, this means that ∠ABC = ∠ACB.

Segments BO and CO bisects ∠ABC and ∠ACB.

And we want to prove that ΔBOC is an isosceles triangle.

Since BO and CO are the angle bisectors of ∠ABC and ∠ACB, respectively, it means that ∠ABO = ∠CBO and ∠ACO = ∠BCO.

And since ∠ABC = ∠ACB, this implies that:

∠ABO = ∠CBO =∠ACO = ∠BCO.

This is shown in the figure as each angle having only one tick mark, meaning that they are congruent.

So, we know that:

$\angle ABC=\angle ACB$

∠ABC is the sum of the angles ∠ABO and ∠CBO. Likewise, ∠ACB is the sum of the angles ∠ACO and ∠BCO. Hence:

$\angle ABO+\angle CBO =\angle ACO+\angle BCO$

Since ∠ABO =∠ACO, by substitution:

$\angle ABO+\angle CBO =\angle ABO+\angle BCO$

Subtracting ∠ABO from both sides produces:

$\angle CBO=\angle BCO$

So, we've proven that the two angles are congruent, thereby proving that ΔBOC is indeed an isosceles triangle.

7 0

3 years ago

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