Use the linear combination method to solve this system of equations. what is the value of x?
3x + 7y = 31
-3x - 2y =-1

a) -6
b) -3 2/3
c) 3 2/3
d) 6

For this case we have the following system of equations:

We multiply the first equation by 2:

We multiply the second equation by 7:

We add the equations:

We convert to a mixed number:

The value of x is

Option B

geometry: triangles

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call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

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