This is so wasy n u dk how to do it u just add 3 my god
Answer:
3-10-(15) equals 8.
Step-by-step explanation:
3-10 equals -7. Then -(-15) becomes a positive because two negatives make a positives producing +15 so it becomes -7+15 which finally becomes 8.
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.
<h2>
Explanation:</h2>
Let's use a trial and improvement method to find this solution.
Step 1. Let's choose x = 8.5
Substituting into the equation:

Step 2. Let's choose x = 8.4
Substituting into the equation:

Step 3. Let's choose x = 8.3
Substituting into the equation:

Since the sign of the equation changes from positive to negative when evaluating from 8.4 to 8.3, then x = 8.3 seems to be a reasonable value. Finally, the solution to 1 decimal place is:
Answer:
i think its 105
Step-by-step explanation: