I believe the next one would be 13.2 because if you add 8.4 to -6.4 it gets 4.8 so you just do the same thing
Answer: 32.14 after round off it will be 32
Step-by-step explanation:
This is how to round 32.14 to the nearest whole number. In other words, this is how to round 32.14 to the nearest integer.
32.14 has two parts. The integer part to the left of the decimal point and the fractional part to the right of the decimal point:
Integer Part: 32
Fractional Part: 14
Our goal is to round it so we only have an integer part using the following rules:
If the first digit in the fractional part of 32.14 is less than 5 then we simply remove the fractional part to get the answer.
If the first digit in the fractional part of 32.14 is 5 or above, then we add 1 to the integer part and remove the fractional part to get the answer.
The first digit in the fractional part is 1 and 1 is less than 5. Therefore, we simply remove the fractional part to get 32.14 rounded to the nearest whole number as:
32
The formula of an area of a square:

a - a side
We have 
substitute:

Used:

First you want to write 7x as a sum or difference: 15x-8x
Now, the expression would look like this: 10x^2+15x-8x-12
Next, factor out the 5x and -4 from the expression: 5x(2x+3)-4(2x+3)
Now, factor out the 2x+3 from the expression and you have your answer:
(2x+3)(5x-4)