Answer:
(0,0)
Step-by-step explanation:

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
The area for a circle with a diameter of 8 cm is 50.24 cm². The area of a circle with a radius of 3 cm is 28.26 cm². 50.24 - 28.26 = 21.98 cm. So the difference is 21.98 cm.
Answer:
D
Step-by-step explanation:
All we need to know is that there are 2 PASTRIES, this makes it to where we can exclude any equation multiplying against two tea cups. Thus making D the only answer correct.