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Marta_Voda [28]

3 years ago

9

How to complete equation and tell property with 21blank =921

1 answer:

LenaWriter [7]3 years ago

5 0

21*x=9*21

9*21=189

21*x=189

Divide 189 by 21 to solve for X or in this case "Blank"

189/21= 9

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Identify the polygon with vertices A(5,0), B(2,4), C(−2,1), and D(1,−3), and then find the perimeter and area of the polygon. HE

inn [45]

Answer:

Part 1) The polygon is a square

Part 2) The perimeter is equal to $20\ units$

Part 3) The area is equal to $25\ units^{2}$

Step-by-step explanation:

we have

$A(5,0), B(2,4), C(-2,1),D(1,-3)$

Plot the points

see the attached figure

we know that

the formula to calculate the distance between two points is equal to

$d=\sqrt{(y2-y1)^{2}+(x2-x1)^{2}}$

Find the distance AB

$A(5,0),B(2,4)$

substitute in the formula

$d=\sqrt{(4-0)^{2}+(2-5)^{2}}$

$d=\sqrt{(4)^{2}+(-3)^{2}}$

$d=\sqrt{25}$

$AB=5\ units$

Find the distance BC

$B(2,4), C(-2,1)$

substitute in the formula

$d=\sqrt{(1-4)^{2}+(-2-2)^{2}}$

$d=\sqrt{(-3)^{2}+(-4)^{2}}$

$d=\sqrt{25}$

$BC=5\ units$

Find the distance CD

$C(-2,1),D(1,-3)$

substitute in the formula

$d=\sqrt{(-3-1)^{2}+(1+2)^{2}}$

$d=\sqrt{(-4)^{2}+(3)^{2}}$

$d=\sqrt{25}$

$CD=5\ units$

Find the distance AD

$A(5,0),D(1,-3)$

substitute in the formula

$d=\sqrt{(-3-0)^{2}+(1-5)^{2}}$

$d=\sqrt{(-3)^{2}+(-4)^{2}}$

$d=\sqrt{25}$

$AD=5\ units$

we have that

AB=BC=CD=AD

Find the distance BD (diagonal)

$B(2,4),D(1,-3)$

substitute in the formula

$d=\sqrt{(-3-4)^{2}+(1-2)^{2}}$

$d=\sqrt{(-7)^{2}+(-1)^{2}}$

$BD=\sqrt{50}\ units$

<em>Verify if the polygon is a square</em>

If the triangle BDA is a right triangle, then the polygon is a square

Applying the Pythagoras theorem

$BD^{2}=AD^{2}+AB^{2}$

substitute

$(\sqrt{50})^{2}=5^{2}+5^{2}$

$50=50$ -----> is true

so

The triangle BDA is a right triangle

therefore

The polygon is a square

<em>Find the Area of the polygon</em>

The area of a square is equal to

$A=b^{2}$

we have

$b=5\ units$

$A=5^{2}=25\ units^{2}$

<em>Find the perimeter of the polygon</em>

The perimeter of a square is equal to

$P=4b$

we have

$b=5\ units$

$P=4(5)=20\ units$

6 0

3 years ago

Factor the trinomial in to 2 sets of parentheses <br> 12a squared minus 13a minus 35

Juliette [100K]

It can't be factored because there are no 2 numbers that when you multiply you get 35 and when you add you get 13.

8 0

3 years ago

If the dimensions of a pentagonal prism are quadrupled, then the surface area of the prism is multiplied by eight.

Lubov Fominskaja [6]

Answer:

false

Step-by-step explanation:

the relationship between lengths/dimensions and areas is that areas are created by multiplying 2 dimensions.

when you quadruple (×4) the dimensions, then the areas are growing with the square of the factor (×4×4 = ×16), because the factor goes twice into the multiplication : one time for every dimension involved.

so, quadrupling the dimensions would multiply the areas by 16.

8 0

3 years ago

What is a factor of 15 but not a multiple of 3

11111nata11111 [884]

45
15 is a multiple of 3
30 is a multiple of 3
45 is NOT a multiple of 3
60 is a multiple of 3
Ect.

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3 years ago

Solve the following equation for x. 7x^2-112=0

xxMikexx [17]

Answer:

x = 4 or x = -4

Step-by-step explanation:

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3 years ago