Answer:
7r³ - 3r² + 20r
Step-by-step explanation:
(9r³ + 5r² + 11r) + (-2r³ + 9r - 8r²)
You can get rid of the parentheses since there is nothing to distribute.
9r³ + 5r² + 11r - 2r³ + 9r - 8r²
Combine like factors.
7r³ - 3r² + 20r
Answer: 
Step-by-step explanation:
For this exercise you need to use the following formula for calculate the area of regular polygon:

Where is "s" the length of any side, "n" is the number of sides.
Int this case you know that it is regular pentagon, which means that it has five sides. Then you can identify that the values of "n" and "s":

Therefore, substituitng values into the formula, you get that the area f the pentagon is:

The answer is 474 i believe
To solve we need to use Pythagoras theorem (

)
There are 2 possible lengths for x: hypotenuse or one of the 2 shorter sides.
Hypotenuse:
10^{2} + 21^2 =

100+441=

23.3≈x
Shorter leg:



= 441-100

x≈18.47
Answer:
Tan C = 3/4
Step-by-step explanation:
Given-
∠ A = 90°, sin C = 3 / 5
<u>METHOD - I</u>
<u><em>Sin² C + Cos² C = 1</em></u>
Cos² C = 1 - Sin² C
Cos² C = 
Cos² C = 
Cos² C = 
Cos C = 
Cos C = 
As we know that
Tan C = 
<em>Tan C =
</em>
<em>Tan C =
</em>
<u>METHOD - II</u>
Given Sin C = 
therefore,
AB ( Height ) = 3; BC ( Hypotenuse) = 5
<em>∵ ΔABC is Right triangle.</em>
<em>∴ By Pythagorean Theorem-</em>
<em>AB² + AC² = BC²</em>
<em>AC² </em><em>= </em><em>BC² </em><em>- </em><em> AB</em><em>² </em>
<em>AC² = 5² - 3²</em>
<em>AC² = 25 - 9</em>
<em>AC² = 16</em>
<em>AC ( Base) = 4</em>
<em>Since, </em>
<em>Tan C =
</em>
<em>Tan C =
</em>
<em>Hence Tan C =
</em>
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