Question

420/x = 120/x+4 - 5​

Answer 1

Explicación paso a paso:

420/x = 120/x+4 - 5

420/x = [120 - 5(x+4)]/x + 4

420/x = (120 - 5x - 20)(x + 4)

420(x + 4) = x(100 - 5x)

420x + 1680 = 100x - 5x^2

5x^2 + 320x + 1680 = 0