4( 10x - 24)² - 8( 10x - 24) + 4 = 0
4( 100x² - 480x + 576) - 80x + 192 + 4 = 0
400x² - 1920x + 2304 - 80x + 196 = 0
400x² - 2000x + 2500 = 0
4x² - 20x + 25 = 0
D = b² - 4ac = 400 - 4 × 4 × 25 = 400 - 400 = 0 - имеет один корень.
x = - b/2a
x= 20 / 8 = 2,5
Ответ: x = 2,5.