She made the mistake of grouping unlike terms and factorizing.
Given that
Helene is finding the sum (9 + 10i) + (–8 + 11i).
She rewrites the sum as (–8 + 11)i + (9 + 10)i.
We have to determine
Which statement explains the property of addition that she made an error in using?
According to the question
The mistake she did is in the second term distributing.
(9+10i) is not equal to (9+10)i
Similarly (-8+11i) is not equal to (-8+11)i.
The correct method she should have done is given below;
Grouping real terms together and imaginary terms together and finding the sum is,

Hence, she made the mistake of grouping unlike terms and factorizing.
To know more about Complex Number click the link given below.
brainly.com/question/10078818
 
        
             
        
        
        
Answer:
Fourth Quadrant
Step-by-step explanation:
a>0 = a is a positive number = +y
b<0 = b is a negative number = -x
[-b,-a] = [-(-x), -(+y)] = [x, -y] 
[positive, negative] is on the fourth quadrant
 
        
             
        
        
        
The profit should be shared in proportion to Mr Jones, Mr Thomas and Mr forson capitals in the ratio 21 : 32 : 27 respectively.
<h3>Proportion</h3>
- Mr Jones capital = $12600
- Mr Thomas capital =$19200
- Mr forson capital = $16200
Total capital = $12600 + $19200 + $16200
= $48,000
Mr Jones proportion = $12600 / $48,000
= 21/80
Mr Thomas proportion = $19200 / $48,000
= 32/80
Mr forson proportion = $16200 / $48000
= 27/80
Learn more about proportion:
brainly.com/question/1781657
$SPJ1
 
        
             
        
        
        
Answer:
Mean = 90, Median = 93, Mode = 90, Range = 6
Step-by-step explanation:
Mean:
96 + 90 + 94 + 93 + 90 = 463
463 ÷ 5 = 92.5
92.5 to nearest tenth = 90
Mean = 90 
Median:
<em>90, 90</em>, <u>93</u>, <em>94 ,96</em>
Median = 93
Mode 
<em>96, </em><u>90</u><em>, 94, 93, </em><u>90</u><em> </em>
Mode = 90
 
Range: 
96 - 90 = 6
Range = 6
 
        
             
        
        
        
2/9 + 1/3 + 2/3
2/9 + 3/9 + 6/9
(2 + 3 + 6) /9
11/9