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icang [17]
4 years ago
5

Simplify the expression (4 + 5i)(4 − 5i). 16 − 20i 16 + 20i −9 41

Mathematics
1 answer:
Alja [10]4 years ago
5 0

Answer:

41

Step-by-step explanation:

Simplify the following:

(5 i + 4) (-5 i + 4)

Hint: | Multiply 4 + 5 i and 4 - 5 i together using FOIL.

(4 + 5 i) (4 - 5 i) = (4) (4) + (4) (-5 i) + (5 i) (4) + (5 i) (-5 i):

4×4 + 4 (-5 i) + 5 i×4 + 5 i (-5 i)

Hint: | Multiply 4 and 4 together.

4×4 = 16:

16 - 5×4 i + 5 i×4 + 5 i (-5)×i

Hint: | Multiply 4 and -5 together.

4 (-5) = -20:

16 + -20 i + 5 i×4 + 5 i (-5)×i

Hint: | Multiply 5 and 4 together.

5×4 = 20:

16 - 20 i + 20 i + 5 i (-5)×i

Hint: | Combine products of like terms.

5 i (-5)×i = 5 i^2 (-5):

16 - 20 i + 20 i + -5×5 i^2

Hint: | Evaluate i^2.

i^2 = -1:

16 - 20 i + 20 i - 5×5×-1

Hint: | Multiply 5 and -1 together.

5 (-1) = -5:

16 - 20 i + 20 i - 5-5

Hint: | Multiply -5 and -5 together.

-5 (-5) = 25:

16 - 20 i + 20 i + 25

Hint: | Evaluate 16 - 20 i + 20 i + 25.

16 - 20 i + 20 i + 25 = 41:

Answer:  41

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This gives us a denominator of 35b³c.
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3 years ago
This is important please help I will give brainiest to people who get both​
ahrayia [7]

Answer:

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Second question is C.

Step-by-step explanation:

First question is correct because non-linear graphs look just like that.

Second question is correct because 2 variables cannot equal the same thing in a function.

7 0
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PLZ HELP FAST ! find the value of x
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Step-by-step explanation:

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4 0
4 years ago
Find the slope of the surface in the x and y-directions at the given point. h(x,y) = x2 – y2 (-3, 2, 5)
belka [17]
If h(x,y)=x^2-y^2, then you can find partial derivatives: 
\frac{dh}{dx} =2x  \\  \frac{dh}{dy} =-2y.

At point A(-3,2,5) (this is the point which lies on the surface, because 5=(-3)^2-2^2=9-4=5) these derivatives have values:

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8 0
3 years ago
Find [g *h](x) and [h*g](x) . g(x) = 5x h(x) = –10x3 + 13x2 – 3x + 3
Llana [10]

Answer:

(g ο h)(x) = -50x³ + 65x² - 15x + 15

(h ο g)(x) = -1250x³ + 325x² - 15x + 3 ⇒ 3rd answer

Step-by-step explanation:

* Lets explain the composite function

- A composite function is a function that depends on another function

- A composite function is created when one function is substituted into

another function  

- Example:

# (f ο g)(x) is the composite function that is formed when g(x) is  

 substituted for x in f(x).

* Now lets solve the problem

∵ g(x) = 5x

∵ h(x) = -10x³ + 13x² - 3x + 3

- To find (g ο h)(x) replace x in g by h(x)

∴ Replace x by -10x³ + 13x² - 3x + 3

∴ (g ο h)(x) = 5(-10x³ + 13x² - 3x + 3)

∴ (g ο h)(x) = -50x³ + 65x² - 15x + 15

- To find (h ο g)(x) replace each x in -10x³ + 13x² - 3x + 3  by g(x)

∴ Replace each x in -10x³ + 13x² - 3x + 3 by 5x

∴ (h ο g)(x) = -10(5x)³ + 13(5x)² - 3(5x) + 3)

∴ (h ο g)(x) = -10(125x³) + 13(25x²) - 15x + 3

∴ (h ο g)(x) = -1250x³ + 325x² - 15x + 3

* (g ο h)(x) = -50x³ + 65x² - 15x + 15

 (h ο g)(x) = -1250x³ + 325x² - 15x + 3

5 0
3 years ago
Read 2 more answers
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