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velikii [3]
3 years ago
14

Expand (3x+7)(3x-7) =

Mathematics
2 answers:
saveliy_v [14]3 years ago
8 0

Answer:

9 {x}^{2}  - 49

Step-by-step explanation:

Do FOIL, first outside inside last

3x × 3x = 9x^2

3x × -7 = -21x

7 × 3x = 21x

7 × -7 = -49

9 {x}^{2}   - 21x + 21x - 49 \: midde \: cancels \: each \: other \: out

So it would just be 9x^2 - 49

Tamiku [17]3 years ago
8 0

(3x + 7)(3x - 7) =

= 9x² + 21x - 21x - 49

= 9x² - 49

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AABC has vertices at A(12, 8), B(4,8), and C(4, 14).
borishaifa [10]

Answer:

<u>Triangle ABC and triangle MNO</u> are congruent. A <u>Rotation</u> is a single rigid transformation that maps the two congruent triangles.

Step-by-step explanation:

ΔABC has vertices at A(12, 8), B(4,8), and C(4, 14).

  • length of AB = √[(12-4)² + (8-8)²] = 8
  • length of AC = √[(12-4)² + (8-14)²] = 10
  • length of CB = √[(4-4)² + (8-14)²] = 6

ΔMNO has vertices at M(4, 16), N(4,8), and O(-2,8).

  • length of MN = √[(4-4)² + (16-8)²] = 8
  • length of MO = √[(4+2)² + (16-8)²] = 10
  • length of NO = √[(4+2)² + (8-8)²] = 6

Therefore:

  • AB ≅ MN
  • AC ≅ MO
  • CB ≅ NO

and ΔABC ≅ ΔMNO by SSS postulate.

In the picture attached, both triangles are shown. It can be seen that counterclockwise rotation of ΔABC around vertex B would map ΔABC into the ΔMNO.

3 0
4 years ago
Mrs. Hawk assigns her students an average of no more than 5 questions on each assignment. On their first 5 assignments Mrs. Hawk
bixtya [17]
Given that <span>Mrs. Hawk assigns her students an average of no more than 15 questions on each assignment. On their first 5 assignments Mrs. Hawk’s students had 11, 10, 13, 14, and 14 questions.

Let x be the number of questions she can have on the sixth assignment, then the inequality that Mrs. Hawk can use to determine the number of questions she can have on the sixth assignment is given by

\frac{11+10+13+14+14+x}{6} \leq15 \\  \\ \Rightarrow62+x\leq90 \\  \\ \Rightarrow x\leq28</span>
5 0
4 years ago
X-3y=1<br> -x+6y=-7<br><br> Solve the system using elimination <br> Type ordered pair
Vedmedyk [2.9K]

Answer:

x=-5, y=-2. (-5, -2).

Step-by-step explanation:

x-3y=1

-x+6y=-7

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

3y=-6

y=-6/3

y=-2

x-3(-2)=1

x+6=1

x=1-6

x=-5

3 0
3 years ago
Given m||n, find the value of x.<br> (9x-5)(6x+20)
xxTIMURxx [149]

Answer:

5/9 & -10/3

Step-by-step explanation:

Set each to 0 and solve:

9x-5 = 0

9x=5

x=5/9

6x+20=0

6x=-20

x=-20/6

x= -10/3   or -3 1/3

7 0
3 years ago
4th time posting this dont skip need help ASAP and pls hurry bc i dont have much time i will give 10 pts + brainliest
Artemon [7]

Answer:

i think it is c but not sure

Step-by-step explanation:

3 0
3 years ago
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