2x * 6 = 5 * 3
12x = 15
x = 15 : 12
x = 1,25
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5x * 3 = 12 * 2
15x = 24
x = 24 : 15
x = 1,6
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4 * x = 3 * 8/9
4x = 8/3
x = 8/3 * 1/4
x = 2/3