Find the value of x for which ABCD must be a parallelogram.
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Answer:
x = 5
Step-by-step explanation:
Property of a parallelogram says that opposite sides of the parallelogram are equal and parallel to each other.
Therefore, BC = AD
(5x - 8) = (2x + 7)
(5x - 8) - 2x = (2x + 7) - 2x
(5x - 2x) - 8 = (2x - 2x) + 7
3x - 8 = 7
(3x - 8) + 8 = 7 + 8
3x = 15
x = 5
Therefore, x = 5 is the answer.