4n² - 16n - 84 = 0
Multiply both sides by 1/4 :
n² - 4n - 21 = 0
Add 21 to both sides:
n² - 4n = 21
Complete the square by adding 4 to both sides:
n² - 4n + 4 = 25
(n - 2)² = 25
Solve for n :
n - 2 = ± √25
n - 2 = ± 5
n = 2 ± 5
Then n = 2 + 5 = 7 or n = 2 - 5 = -3.
<span>If 7 dancers were at a dance and 46 more came in and h left and there was 13 dancers left how many was h
</span>- h is 70.
Answer:
(-1,6)
Step-by-step explanation:
Explanation is in the photo
Answer:
There are four addition properties that help to add whole numbers :
For any whole number a, b, and c ;
1. <u>Closure property of addition </u>- 
For example:
2+3=5
4+3=7
We can conclude that if we add any two whole number , we get another whole number.
2. <u>Associative property of addition</u>- when any whole number or variable are added, then that can be grouped in different way without changing result

For example:
2+(3+4)=(2+3)+4
3.<u> </u><u>Commutative property of addition</u>- when any whole number or variable are added, then the order changed without changing the result.

For example: 2+3=3+2
4. <u>Identity property of addition</u>- when 0 is added to a whole number or variable , the result is the same variable or number.

For example: 3+0=0+3
0 is called an Identity for addition of whole numbers.