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PLEASE HELP ill reward a lot

PLEASE HELP ill reward a lot-example-1
User Tary
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2 Answers

2 votes
x^2-x-2=0

x^2-2*(1/2)x+(1/2)^2-1/4-2=0

x^2-2*(1/2)x+(1/2)^2=9/4

(x-1/2)^2=9/4

x-1/2=3/2 or -3/2

x=2 or -1

User Yizhar
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3.7k points
1 vote

Answer:

• from the quadratic formula:


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

• a → 1, b → 1, c → -2:

• substitute:


{ \tt{x = \frac{ - 1± \sqrt{ {1}^(2) - (4 * 1 * - 2) } }{(2 * 1)} }} \\ \\ { \tt{x = ( - 1± √(9) )/(2) }} \\ \\ { \tt{x = ( - 1±3)/(2) }}

• Find values of x:


{ \boxed{ \tt{x = ( - 1 + 3)/(2) }}} \: \: { \tt{and}} \: \: { \boxed{ \tt{x = ( - 1 - 3)/(2) }}} \\ \\ { \boxed{ \tt{x = 1}}} \: \: { \tt{and}} \: \: { \boxed{ \tt{x = - 2}}}

User Mburm
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