Question

Q. Solve using the quadratic formula x2 + 4x – 16 = 0 ?

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answer choices
2 + 25
A
B 2 + 4V5
C -2 + 275
D -2 + 4V5

Answer 1

Explanation:

ax² + bx + c = 0

`x_(1)` =
`(-b - √(b^2 -4ac) )/(2a)`

`x_(2)` =
`(-b+√(b^2 -4ac) )/(2a)`

~~~~~~~~~~~~~~~~~~~

x² + 4x - 16 = 0

a = 1 , b = 4 , c = - 16

`x_(1)` = ( - 4 -
`√(16+64)` ) ÷ 2 = - 2 - 4√5

`x_(2)` = - 2 + 4√5