Resolva as equações do Segundo Grau...?

annelym

A)4.(x-2).(x-8)=(8-x)

B)6(y-3)²=(y-9).(3-y)

ji-vii

A)

4 ( X - 2 ) • ( X - 8 ) = ( 8 - X )

( 4X - 8 ) • ( X - 8 ) = ( 8 - X )

4X² - 32X - 8X + 64 = 8 - X

4X² - 32X - 8X + 64 - 8 + X = 0

4X² - 32X - 8X + X + 64 - 8 = 0

4X² - 39X + 56 = 0

a = 4

b = - 39

c = 56

Δ = b² - 4ac

Δ = ( - 39 )² - 4 • 4 • 56

Δ = 1521 - 896

Δ = 625

X = ( - b ± √Δ ) / ( 2a )

X = ( 39 ± √625 ) / ( 2 • 4 )

X = ( 39 ± 25 ) / 8

X' = ( 39 + 25 ) / 8

X' = 64 / 8

X' = 8

X'' = ( 39 - 25 ) / 8

X'' = 14 / 8

X'' = 7 / 4