Question

1)5x^2-18x+16
2)3x^2-11x-14
3)x^2-x-1
решить через дискриминант

Answer 1

1) 5x² - 18x + 16 = 0
D = b² - 4ac = 324 - 4 × 5 × 16 = 324 - 320 = 4 = 2²
x1 = ( 18 + 2) / 10 = 2
x2 = ( 18 - 2) / 10 = 1,6

2) 3x² - 11x - 14 = 0
D = b² -4ac = 121 - 4×3×(-14) = 121 + 168 = 289 = 17²
x1 = ( 11 + 17) / 6 = 28/6 = 4 4/6 = 4 2/3
x2 = ( 11 - 17) / 6 = - 1

3) x² - x - 1 = 0
D = b² - 4ac = 1 - 4×(- 1) = 1 + 4 = 5
x1 = ( 1 + √5)/2
x2 = ( 1 - √5) / 2

Answer 2

спасибо

Answer 3

пожалуйста,успехов!