1) x²+2x-63=0D = 2² - 41(-63) = 4 + 252 = 256x1 = (-2 + √256) / 2 = (-2 + 16) / 2 = 14 / 2 = 7x2 = (-2 - √256) / 2 = (-2 - 16) / 2 = -18 / 2 = -9
Ответ: x1 = 7, x2 = -9
2) -7x²-46+21=0D = (-46)² - 4(-7)21 = 2116 + 588 = 2704x1 = (46 + √2704) / (-14) = (46 + 52) / (-14) = 98 / -14 = -7x2 = (46 - √2704) / (-14) = (46 - 52) / (-14) = -6 / -14 = 3/7
Ответ: x1 = -7, x2 = 3/7
3) 25x²-30x+9=0D = (-30)² - 4259 = 900 - 900 = 0x = 30 / 50 = 3/5
Ответ: x = 3/5
4) 2x²+3x+5=0D = 3² - 425 = 9 - 40 = -31x1 = (-3 + √(-31)) / 4x2 = (-3 - √(-31)) / 4
Ответ: x1 = (-3 + √31i) / 4, x2 = (-3 - √31i) / 4
1) x²+2x-63=0
D = 2² - 41(-63) = 4 + 252 = 256
x1 = (-2 + √256) / 2 = (-2 + 16) / 2 = 14 / 2 = 7
x2 = (-2 - √256) / 2 = (-2 - 16) / 2 = -18 / 2 = -9
Ответ: x1 = 7, x2 = -9
2) -7x²-46+21=0
D = (-46)² - 4(-7)21 = 2116 + 588 = 2704
x1 = (46 + √2704) / (-14) = (46 + 52) / (-14) = 98 / -14 = -7
x2 = (46 - √2704) / (-14) = (46 - 52) / (-14) = -6 / -14 = 3/7
Ответ: x1 = -7, x2 = 3/7
3) 25x²-30x+9=0
D = (-30)² - 4259 = 900 - 900 = 0
x = 30 / 50 = 3/5
Ответ: x = 3/5
4) 2x²+3x+5=0
D = 3² - 425 = 9 - 40 = -31
x1 = (-3 + √(-31)) / 4
x2 = (-3 - √(-31)) / 4
Ответ: x1 = (-3 + √31i) / 4, x2 = (-3 - √31i) / 4