Question

Calcule;

a) ( x + 2 ). ( x – 2)= b) (x + 2 ). (x + 2 )=

c) ( x – 2 ). (x – 2 ) = d) ( 2x – 5 ) . ( 2x + 5 )=

e) ( x –1 )³= f) ( x + 1 )³​

Answer 1

Resposta:

A)x=2

B)x = -2

C) x=2

D)1,25

F)3

Explicação passo-a-passo:

a)( x + 2 ). ( x – 2)= x²-2x+2x-4 = x²-4=0

x²=+4 x=✔4=2

b) (x + 2 ). (x + 2 )= -4+0 -2

x²+2x+2x+4=0 ------

x²+4x+4=0 2

=b²-4•a•c

x=-b+-✔ = -4+-0 = -4 - 0 = -2 =4²-4•1•4 2•a 2 2

= 16-16

=0

c) ( x – 2 ). (x – 2 )

x²-2x-2x+4

x²-4x+4

=b²-4•a•c ×=4+-0= x=4+0 x=4 = 2

=(-4²)-4•1•4 2•1 2 2

=16-16

=0

d)( 2x – 5 ) . ( 2x + 5 )

4x²+10x-10x-25

4x²-25=0

4x²=25

4x=✔25 =5

x =5 = 1,25

4

E)( x –1 )³= 3

(x-1)•(x-1)•(x-1)

x²-1x-1x+1 •(x-1)

x²-2x+1•(x-1)

x³-x²-2x²+2x+1x-1

x³-3x²+3x-1=0 ---> equação de 3°

F) ( x + 1 )³

(x+1)•(x+1)•(x+1)

x²+1x+1x+1•(x+1)

x²+2x+1•(x+1)

x³+x²+2x²+2x+1x+1

x³+3x²+3x+1 ------> equação do 3°