Step-by-step explanation:
1) -9 = 9 true/false
the answer is false because negative and positive quite unlike in terms.
2) -(-21) = -21
Using the symbols multiplication rule,
Where,
<h2>
+ × + = +</h2><h2>
- × - = +</h2><h2>
- × + = -</h2><h2>
+ × - = -</h2>
Therefore, -(-21) = +21 = 21
⟼ 21 = -21 
#3 is a triangular pyramid because triangular pyramids have 4 triangular faces.
#4 is a cube because there are 6 square faces.
#5 is a triangular prism. It has 2 triangular faces and 3 rectangular faces.
#6 is a rectangular prism. It has 2 square faces and 4 rectangular faces.
(If you don't know what the figure of the net is, resketch it on another piece of paper, cut it out, and form it.)
Hope this helps,
Loafly
What 2 # multiplied together make 28,
7x4
2x14 out of these which one has one side 3ft. more? 7x4
mu = 1100 = population mean
sigma = 275 = population standard deviation
x = 1400 = raw score
z = z score
z = (x-mu)/sigma
z = (1400-1100)/(275)
z = 300/275
z = 1.0909090909091 approximately
z = 1.09
Convention is to round to two decimal places so that you can use a Z table to look up the area under the curve (which helps determine probability).
The positive z score is due to Paula's raw score being above the mean.
Yes it determine the length