→ net fish 17x/20kg,
→ Fish pieces 3x/5, head and tail = x/4, sold at x/2 (yuan),
→ The fuel consumption is 750× 3x/5 ÷ 4.8 = 4,500x/48 (grams), and the cost is 4.5x/48×2×9 = 8 1x/48 (yuan).
→ spiced fried fish pieces 3x/5x3.5/4.8 = 105x/240 (kg) = 105000x/240 (g)
=1050x/240 = 35x/8 (100g).
Total cost = xy+81x/48-x/2 = x (y+57/48), and 35x/8g spiced fried fish pieces were obtained.
Unit cost = x (y+57/48) ÷ (35x/8) = 8 (y+57/48)/35 (yuan/100g).
The formula for finding roots is a mathematical formula for directly expressing roots by the coefficients of equations. This formula was given by Alhualamo in Central Asia as early