Answer:
D
Step-by-step explanation:
(I solved in the picture, firstly look at there)
after completing the square and factoring :



Hope this helps ^-^
7(3a + 12) = 168 ← ( divide both sides by 7 )
3a + 12 = 24 ← ( subtract 12 from both sides )
3a = 12 ← ( divide both sides by 3 )
a = 4
OR
distribute the parenthesis by 7
21a + 84 = 168 ← ( subtract 84 from both sides )
21a = 84 ← ( divide both sides by 21 )
a = 4
The answer is 15 cause you start at 15 and go from there
Given the expression (8+3i)+(-2+i)
We need to simplify it.
(8+3i)+(-2+i)
First we have to remove the parenthesis.
8+3i-2+i
As we know that multiplication of positive and negative is negative.
Now we will add or subtract like terms. Like terms means here i with i and constant term with constant term. So here we will add 3i and i. Also subtract 2 from 8.
8-2 +3i+i
6+4i
We have got the required answer.
The simplified answer is 6+4i.
4.85 is the answer because if you subtract 51.2 from 56.05 you get your answer