Question

Como resolver??( x-5) (x+5)+5=x???

Answer 1

( x - 5 ) . ( x + 5 ) + 5 = x
x^2 + 5x - 5x - 25 + 5 = x
x^2 - x - 20 = 0

Báskara:

b^2 - ( 4 ) . ( a ) . (c )
( 1 )^2 - ( 4 ) . ( 1 ) . ( -20 )
1 + 80
81

x = - ( b ) +/- raizBáskara / 2
x = - ( - 1 ) +/- raiz81 / 2
x = 1 +/- 9 / 2

x' = 1 + 9 / 2
x' = 10 / 2
x' = 5

x" = 1 - 9 / 2
x" = -8 / 2
x" = -4

Conjunto solução: |5| |-4|

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