Question

What is 4x+2/39=5x-2/42?

Answer 1

We use the fundamental property of proportions where:

• a/b = c/d if a • d = b • c

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`\bf (4x + 2)/(39) = (5x - 2)/(42) \\ \\ \bf 39 \cdot (5x - 2) = 42 \cdot (4x + 2) \\ \\ \bf 195x - 78 = 168x + 84 \\ \\ \bf 195x - 168x = 84 + 78 \\ \\ \bf 27x = 162 \\ \\ \bf x = (162)/(27) \implies \bf \red{ \boxed{ \bf x = 6} }`

The number is 6.

Hope that helps! Good luck! :)