Answer:
-2.6
Step-by-step explanation:
10.9 + (-15.6) becomes 10.9 - 15.6 which equals -4.7. The last step is to add the 2.1 to the -4.7: -4.7 + 2.1 = -2.6
Therefore the answer is -2.6
12 the answer is 12 I know it
In expanded form, the number would look like this:
300,000,000 + 10,000,000 + 700,000 + 60,000 + 3,000 + 100 + 40 + 6
When you add the value of all of these digits, it'll get you the number: 310,763,146. Adding all of these values up and getting the number you originally started with is a great method of making sure you got the right answer.
Answer:
36 : 6 and -6
12 = 
1.96 =1.4 and -1.4
0.64 : 0.8 and -0.8
400 : 20 and -20
25/36 = 5/6 and -5/6
Step-by-step explanation:
we know that
(-x)^2 = x^2
ALSO
(x)^2 = x^2
thus, square of both negative and positive number is same positive number.
_________________________________________________
36 = 6*6
36 = -6*-6
hence
square roots of 36 is both -6 and 6
12 = 4*3 =

also
12 = 

___________________________________
1.96 = 196/100 = (14/10)^2
1.96 = 196/100 = (-14/10)^2
hence

_______________________________
0.64 = 64/100 = (8/10)^2 = 0.8^2
0.64 = 64/100 = (-8/10)^2 = (-0.8)^2
Thus, square root of 0.64 = 0.8 and -0.8
_________________________________
400 = 20^2
400 = (-20)^2

__________________________________
25/36 = (5/6)^2
25/36 = (-5/6)^2

For my answer, I got -47 1/2