Answer: 16
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Explanation:
The diagonal pieces are 28 and 21. They pair up to get the fraction 28/21
The horizontal pieces are x and 12, in the same order from left to right. The order is important (so things pair up properly). We get the fraction x/12
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Set the two fractions equal to each other and solve for x
28/21 = x/12
28*12 = 21*x .... cross multiply
336 = 21x
21x = 336
x = 336/21 .... divide both sides by 21
x = 16
