Answer:
Read below.
Step-by-step explanation:
Wrong:
(2.5 x 10^9) + (5.3 x 10^8) =
(2.5 + 5.3) x (10^9 x 10^8)
=
7.8 x 10^7=
7.8 x 10,000,000=
780,000,000
<u>Bold is edited by me</u>
Correct:
(2.5 x 10^9) + (5.3 x 10^8)=
(2.5 x 1,000,000,000)+(5.3 x 100,000,000)=
2,500,000,000+5,300,000,000=
7,800,000,000
The problem is that whoever wrote it swapped the numbers in the parentheses, added a pair of them together and multiplied the other pair. You are not supposed to take out the pairs and swap them if you'd like or the answer is incorrect. Second mistake is that 
is not 
I do not know how and where you got that answer from.
Answer:
C. II only
Step-by-step explanation:
Basically all you need do is plug these answers in and if the complete the inequality to make a true statement.
Yes i know no body want to do that but that whats need to be done lol.
once i plug 7 12/7+8 = 12.83
12.83>20
is incorrect
so we need continue
7*2.5+8>20
7*2.5= 17.5
17.5+8= 25.5
25.5>20
this a true statement
so we know 2.5 is an answer
now we need plug in -3
7*-3= -21
-21 +8 = -13
-13>20
this is incorrect
Answer:
Step-by-step explanation:
If needed line is perpendicular to the line 
then its slope satisfies condition
Then the equation of needed line will have look
Since this line passes through the point (-4,-1), then
Hence, the equation is
