X2 - 7x + 9 =0 please leave answer in surf form and simplify

Question

asked Feb 12, 2021 83.0k views

2 Answers

Arets Paeglis · Answer 1 · 2021-02-18T08:23:15+0000

Answer:

x =
(7)/(2) ±
(√(13) )/(2)

Explanation:

Given

x² - 7x + 9 = 0 ( subtract 9 from both sides )

x² - 7x = - 9

Solve using the method of completing the square

add ( half the coefficient of the x- term)² to both sides

x² + 2( -
(7)/(2) )x +
(49)/(4) = - 9 +

(x -
(7)/(2) )² =
(13)/(4) ( take the square root of both sides )

x -
(7)/(2) = ±
$\sqrt{(13)/(4) }$ = ±
(√(13) )/(2) ( add

x =
(7)/(2) ±
(√(13) )/(2) =
(7+/-√(13) )/(2)