Problem 1
Assuming this is a parallelogram, this would mean the opposite sides are the same length
2x-10 = x+2
2x-x = 2+10
x = 12 is the answer
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Problem 2
Same assumption as problem 1. If we have a parallelogram, then the opposite angles are the same measure.
3x+12 = 6x-3
12+3 = 6x-3x
15 = 3x
3x = 15
x = 15/3
x = 5 is the answer