Question

(2x-3).(2x+3)=16

Sorry pfv

Answer 1

(2x-3).(2x+3)=16
4x² +6x-6x-9=16
4x²+6x-6x-9-16=0
4x²-25=0
A=4 B=0 C=-25
Δ=B²-4AC
Δ=0²-4.4. (-25)
Δ=0+400
Δ=400

x = [-b ± √Δ]/2a
x = [-0 ± √400]/2.4
x = [-0 ± 20]/8

x'= -0+20/8
x'= 20/8
x'=2,5

x"=-0-20/8
x"=-20/8
x"=-2,5

X=(2,5/-2,5)

Espero ter ajudado.

Answer 2

Olá,

(2x-3)(2x+3) = 16
4x²+6x-6x-9 = 16
4x²-9 = 16
4x² = 16+9
4x² = 25
x² = 25/4

x = √25/4
x = √25/√4
x = 5/2

ou 

x = -√25/4
x = -√25/√4
x = -5/2

Resposta:

x = 5/2 ou x = -5/2