For a simplest fraction, the sum of the numerator and denominator is 80. If the numerator and denominator are all reduced by 4, the value of the new fraction is 5 / 19. What is the original fraction It is required to write down the formula and answer, and explain clearly how it happened

80-X-4/x-4=5/19
X=61
The original score was 19 out of 61

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