Question

X^2+2x+9=0 please?!
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Answer 1

D

Explanation:

Given a quadratic equation in standard form : ax² + bx + c = 0

We can solve for x using the quadratic formula

x² + 2x + 9 = 0 ← is in standard form

with a = 1, b = 2 and c = 9

x = ( - 2 ±
`√(2^2-(4(1)(9))`) / 2

= ( - 2 ±
`√(4-36)`) / 2

= (- 2±
`√(-32)`) / 2)

= (- 2 ±
`√(16(2)(-1))`) / 2

= ( - 2 ± 4i
`√(2)`) / 2

=
`(-2)/(2)` ±
`(4i√(2) )/(2)`

= - 1 ± 2i
`√(2)` → D

Answer 2

Choice D is the answer.

Explanation:

We have given a quadratic equation.

x²+2x+9 = 0

We have to find the solution of given equation.

From given equation, a = 1, b = 2 and c = 9.

x = (-b±√b²-4ac) / 2a is quadratic formula to find the solve quadratic equation.

Putting given values in formula, we have

x = (-2±√(2)²-4(1)(9) ) / 2(1)

x = (-2±√4-36) / 2

x = (-2±√-32) / 2

x = (-2±√16√-2 ) /2

x = (-2±4√2√-1) / 2 ∵ i = √-1

x = 2(-1±2√2i) / 2

x = -1±2√2i is the solution of given solution.