Question

Aiko is finding the sum (4+5i)+(-3+7i). She rewrites the sum as (-3+7)i + (4+5)i. Which statement explains the property of addition that she made an error doing?

a. commutative B.Associative C.Identity D.Distributive

Answer 1

D) Distributive

Explanation:

Given that Aiko is finding the sum (4+5i)+(-3+7i). She rewrites the sum as (-3+7)i + (4+5)i.

She started with the first step

`(4+5i)+(-3+7i)`

Instead of grouping like terms, one set constant and other set the i terms, she used distributive law for both terms wrongly

Correct method would have been

`(4+5i)+(-3+7i)\\=(4-3)+(5i+7i)\\=1+i(5+7)`

Now Alko should have simplified and wrote the answer as

`1+12i`

So answer is

D) Distributive

Answer 2

For this case, Aiko erroneously used the distributive property of the addition.

The correct way to use the distributive property for this case is given by:

`image`

From here, rewriting we have:

`image`

Simplifying we have:

`image`

Answer:

the property of addition that she made an error doing is:

D.Distributive