Answer:
7
Step-by-step explanation:
Formula=area of base x height / 3
A= ( 3 x 1 ) x 7 / 3
A= 3 x 7 / 3
A= 21 / 3
A= 7
1. +
2.divide
3. *
4. Divide
5. -
6. +
7. -
8.*
9. 2 and 5
Answer:
11 * I
Unless you can tell me what I is equal to, I can't give you a number as an answer. Just take what ever I is equal to, an multiply it by 11. If the answer choices are equations rather than numbers, than just say 11 * 1.
If the question comes with any more information, please comment so I can give you a stronger answer.
Hope this helps! :)
-Sophia
Answer:
Joe
Step-by-step explanation:
If you expand out the brackets you get this,
(4+5i)(a+2i) = 4a + (5a)i + 8i - 10
The -10 comes from 5i * 2i.
Squaring i becomes -1.
Let's group the real stuff together,
and imaginary separately,
(4a - 10) + (5a + 8)i
For this to be purely imaginary,
the real part needs to be zero.
Therefore 4a - 10 = 0
Solve for a.
