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2 years ago

Simplify (y + 9)(y - 9). А у2 B у2 - 18 C y2 - 81 D у2 + 81

Mathematics

2 answers:

mestny [16]2 years ago

8 0

Answer:

Answer is y^2-81

Step-by-step explanation:

Varvara68 [4.7K]2 years ago

4 0

Answer:

Step-by-step explanation:

According to formula

(a+b)(a-b)=a²-b²

(y+9)(y-9)

=y²-(9)²

=y²-81

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78! is the answer to this question! trust! -6

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1 year ago

Some body can help me with a geometric mean maze

Mars2501 [29]

Answer:

See explanation

Step-by-step explanation:

Theorem 1: The length of the altitude to the hypotenuse of a right triangle is the geometric mean of the lengths of the segments of the hypotenuse.

Theorem 2: The length of each leg of a right triangle is the geometric mean of the length of the hypotenuse and the length of the segment of the hypotenuse adjacent to that leg.

1. Start point: By the 1st theorem,

$x^2=25\cdot (49-25)=25\cdot 24=5^2\cdot 2^2\cdot 6\Rightarrow x=5\cdot 2\cdot \sqrt{6}=10\sqrt{6}.$

2. South-East point from the Start: By the 2nd theorem,

$x^2=40\cdot (40+5)=4\cdot 5\cdot 2\cdot 9\cdot 5\Rightarrow x=2\cdot 5\cdot 3\cdot \sqrt{2}=30\sqrt{2}.$

3. West point from the previous: By the 2nd theorem,

$x^2=(32-20)\cdot 32=4\cdot 3\cdot 16\cdot 2\Rightarrow x=2\cdot 4\cdot \sqrt{6}=8\sqrt{6}.$

4. West point from the previous: By the 1st theorem,

$9^2=x\cdot 15\Rightarrow x=\dfrac{81}{15}=\dfrac{27}{5}=5.4.$

5. West point from the previous: By the 2nd theorem,

$10^2=8\cdot (8+x)\Rightarrow 8+x=12.5,\ x=4.5.$

6. North point from the previous: By the 1st theorem,

$x^2=48\cdot 6=6\cdot 4\cdot 2\cdot 6\Rightarrow x=6\cdot 2\cdot \sqrt{2}=12\sqrt{2}.$

7. East point from the previous: By the 2nd theorem,

$x^2=22.5\cdot 30=225\cdot 3\Rightarrow x=15\sqrt{3}.$

8. North point from the previous: By the 1st theorem,

$x^2=7.5\cdot 36=270\Rightarrow x=3\sqrt{30}.$

8. West point from the previous: By the 2nd theorem,

$x^2=12.5\cdot (12.5+13.5)=12.5\cdot 26=25\cdot 13\Rightarrow x=5\sqrt{13}.$

9. North point from the previous: By the 1st theorem,

$12^2=x\cdot 30\Rightarrow x=\dfrac{144}{30}=4.8.$

101. East point from the previous: By the 1st theorem,

$6^2=1.6\cdot (x-1.6)\Rightarrow x-1.6=22.5,\ x=24.1.$

11. East point from the previous: By the 2nd theorem,

$20^2=32\cdot (32-x)\Rightarrow 32-x=12.5,\ x=19.5.$

12. South-east point from the previous: By the 2nd theorem,

$18^2=x\cdot 21.6\Rightarrow x=15.$

13. North point=The end.

6 0

2 years ago

Help! Show work please<br>will mark brainliest

Arada [10]

Answer:

x = 62.23 ft

y = 47.67 ft

Step-by-step explanation:

6 0

2 years ago

The length,AB of the rectangular lot is 1 foot less than two times its width, BC. If the perimeter of the rectangular lot 394 fe

r-ruslan [8.4K]

Answer:

$AB=131\ ft$

Step-by-step explanation:

we know that

The perimeter of the rectangular lot is

$P=2(AB+BC)$ ----> equation A

where

AB is the length

BC is the width

we have

$AB=2BC-1$ ---> equation B

$P=394\ ft$ ----> equation C

substitute equation B and equation C in equation A

$394=2(2BC-1+BC)$

solve for BC

$394=2(3BC-1)$

$394=6BC-2$

$6BC=396$

$BC=66\ ft$

<em>Find the value of AB</em>

$AB=2BC-1$

$AB=2(66)-1$

$AB=131\ ft$

6 0

2 years ago

What is the measure of x angles are not necessarily

lisov135 [29]

Answer:

X is 83

Step-by-step explanation:

Subtract 180 because thats what all of them eaqual and you subtract 97 from 180

7 0

2 years ago