-7 times -8 is 56 and -40 divided by 10 is -4
Answer: 
Step-by-step explanation:
Given
The two communication mask are 2 km apart
Ubi's home is 500 m east of one of the mask
Suppose its distance from the other's is x
From the figure, we can write
The answer i found to be is C
Try googling this it will give you some examples and definitions.
https://mathbitsnotebook.com/Geometry/SegmentsAnglesTriangles/SATTriangleTypes.html