x2 - 2x - 7 = 0D = b2 - 4acD = 4 + 28 = 32 = (4√2)^2
x1,2 = -b ± √D/2ax1 = 2 + 4√2/2 = 1 + 2√2x2 = 2 - 4√2/2 = 1 - 2√2ответ: x1 = 1 + 2√2 ; x2 = 1 - 2√2
x2 - 2x - 7 = 0
D = b2 - 4ac
D = 4 + 28 = 32 = (4√2)^2
x1,2 = -b ± √D/2a
x1 = 2 + 4√2/2 = 1 + 2√2
x2 = 2 - 4√2/2 = 1 - 2√2
ответ: x1 = 1 + 2√2 ; x2 = 1 - 2√2