Which expression is equivalent to -1.3 - (-1.9)−1.3−(−1.9)minus, 1, point, 3, minus, left parenthesis, minus, 1, point, 9, right
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Answer:
Choise B: 
Step-by-step explanation:
For this exercise you must remember the multiplication of signs:

By definition, equivalent expression have the same value.
Then, you can find an equivalent expression to the expression provided in the exercise by simplifying it.
So, given:

To simplify it, you can distribute the negative that is located outside of the parentheses (in order to eliminate the parentheses).
Applying this procedure, you get the following equivalent expression:

Therefore, as you can notice, the expression obtained matches with the one shown in Choice B.
ANSWER
The sphere is 10762 cubic centimeters bigger than the cube.
EXPLANATION
We want to find the difference in the volumes of the sphere and the cube.
To do this, we have to find the volumes of the sphere and cube and subtract that of the cube from the sphere.
The volume of a sphere is given as:

where r = radius
The radius of the sphere is 15 centimeters. Therefore, the volume of the sphere is:

The volume of a cube is given as:

where s = length of the side
The length of the side of the cube is 15 centimeters. Therefore, the volume of the cube is:

Therefore, the difference in the volumes of the sphere and cube is:

Therefore, the sphere is 10762 cubic centimeters bigger than the cube.
Where are the measurements?
Answer: 32 meters
Explanation: The 4 meter pole casts a shadow of 5 meters. The towers unknown height casts a shadow of 40 meters. Now isolate the shadows. 5 and 40. 40 divided by 5 is 8, so 4 times 8 is 32.
THe amplitude is half of the distance from the highest and lowest phase of the wave..
4-(-1)=5
0.5*5=2.5
amp=2.5 units