4(x-1)²-3(x-5)(x+5)+x=x(x+7)
4(x - 1)² - 3(x - 5)(x + 5) + x = x(x + 7)
4(x² - 2x + 1) - 3(x² - 25) + x = x² + 7x
4x² - 8x + 4 - 3x² + 75 + x - x² - 7x = 0
- 14x + 79 = 0
- 14x = - 79