Question

Could someone please help me?

Answer 1

Option B

Explanation:

Use the formula

`x = \frac{-b\±\sqrt{b^(2)-4ac } }{2a}`

now input the values. In equation
`x^(2) - 5x + 7 = 0`, a = 1, b = -5 & c = 7

By taking positive sign we get,

`x = \frac{-b+\sqrt{b^(2)-4ac } }{2a}`

⇒
`x = \frac{-(-5)+\sqrt{(-5)^(2)-4.1.7 } }{2.1}`

⇒
`x = (5+√(25-28 ) )/(2)`

⇒
`x = (5+√(-3 ) )/(2)`

In the same way, by taking minus sign, we get
`x = (5-√(-3 ) )/(2)`