Question

решите уравнение 1) 3у2+у=7 2) -х2-3х+1=0​

Answer 1

1)6у+у=7

7у=7

У=1

2)-5х+1=0

- 5х=-1

х=1/5

Answer 2

Объяснение:

1)

3у² + у = 7,

3у² + у - 7 = 0,

Д = 1² - 4*3*(-7) = 1 + 84 = 85,

у1 = (-1 + √85) / 2*3 = (-1 + √85)/6,

у2 = (-1 - √85) / 2*3 = (-1 - √85)/6 = -(1 + √85)/6,

2)

-х² - 3х + 1 = 0​,

Д = (-3)² - 4*(-1)*1 = 9 + 4 = 13,

х1 = (3 + √13) / (-2*1) = -(3 + √13)/2,

х2 = (3 - √13) / (-2*1) = -(3 - √13)/2