Answer: 
<u>Step-by-step explanation:</u>
Pythagorean Theorem is: a² + b² = c² , <em>where "c" is the hypotenuse</em>
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Note: 4² + (8√2)² = hypotenuse² → hypotenuse = 12

Note: 12² + opposite² = 20² → opposite = 16

Note: adjacent² + 5² = 6² → adjacent = √11

Note: adjacent² + 7² = (13√2)² → adjacent = 17
Since there are 6 students out of which one needs to be selected, the principal chose two die on which there are six numbers each numbered from 1 , 2, 3, 4, 5, 6.
Since there are two dice, the total possible outcome is 36.
Hence, the probability of getting one number each is 1/36
Hence, the principal used a fair method because each result is an equally likely possible outcome.
Option B is correct.
To add the two expressions, we can write it as:
4.6x-3 + (-5.3x+9)
We can distribute the plus sign (which means just drop the parenthesis in this case):
4.6x-3-5.3x+9
Now, we can simplify by combining like terms:
-0.7x+6
The answer is 10 cm
Imagine cement cover as a rectangle which volume is 660,000,000 cm3. So this rectangle has width (w = 60m), length (l = 110m), and height (h = ?). The height of the rectangle is actually a thickness of the cement layer. So, we will use the formula for the volume (V) of the rectangle to calculate the thickness:
V = w · l · h
It is given:
V = 660,000,000 cm³
w = 60 m = 60 · 100 cm = 6,000 cm
l = 110 m = 110 · 100 cm = 11,000 cm
h = ?
Using the formula: V = w · l · h
660,000,000 = 6,000 · 11,000 · h
660,000,000 = 66,000,000 · h
⇒ h = 660,000,000 ÷ 66,000,000 = 10 cm
<em><u>3 x 12 </u></em>
<em><u>I think because you find out how to graph in the corresponding area on the graph </u></em>