Answer:
1. In the multiplication of the imaginary parts, the student forgot to square of i. OR
2. The student has only multiplied the real parts and the imaginary parts.
Correct value
.
Step-by-step explanation:
The given expression is

A student multiplies (4+5i) (3-2i) incorrectly and obtains 12-10i.
Student's mistake can be either 1 or second:
1. In the multiplication of the imaginary parts, the student forgot to square of i.
2. The student has only multiplied the real parts and the imaginary parts.

Which is not correct. The correct steps are shown below.
Using distributive property, we get



![[\because i^2=-1]](https://tex.z-dn.net/?f=%5B%5Cbecause%20i%5E2%3D-1%5D)


Therefore, the correct value of
is
.
Answer:
4.43
Step-by-step explanation:
7.90
- 3.47
__________
4. 4 3
I couldn't regroup but of you cross out 0 and put 10, 10-7= 3
and you have to borrow one from 9 and make it 8 and 8-4=4
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Information Given:
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ON = 7x - 9
LM = 6x + 4
MN = x - 7
OL = 2y - 7
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Since it is a parallelogram:
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ON = LM and
MN = OL
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ON = LM:
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7x - 9 = 6x + 4
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Subtract 6x from both sides:
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x - 9 = 4
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Add 9 to both sides:
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x = 13
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MN = OL:
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x - 7 = 2y - 7
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Sub x = 13:
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13 - 7 = 2y - 7
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Simplify:
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6 = 2y - 7
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Add 7 on both sides:
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13 = 2y
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Divide by 2:
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y = 13/2
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Answer: x = 13, y = 13/2 (Answer D)
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Answer:
We have sinθ = 12/13
The method here is to figure out the value of θ
Using a calculator sin^(-1)(12/13) =67.38°
67.38° is in quadrant 1 so we must substract 67.38° from 180° wich is π
- 180-67.38= 112.61° ⇒ θ= 112.61°
Now time to calculate cos2θ and cosθ using a calculator
- cosθ = -5/13
- cos2θ = -0.7
The values we got make sense since θ is in quadrant 2 and 2θ in quadrant 3
Or mine means that itself and 1 can only go into it. Conposit means that multiple numbers can go into it like 24. 12,6,8,2 can all go into it