Question

A= 2x-3 B= 2x+1 qual o valor de A elevado a 2 - B elevado a 2?

Answer 1

A² = (2x - 3)² = 4x² -12x + 9
B² = (2x + 1)² = 4x² + 4x + 1
A² - B² = (4x² -12x + 9) - (4x² +4x + 1)
A² - B² = 4x² -12x + 9 - 4x² -4x - 1
A² - B² = 4x² - 4x² -12x -4x + 9 - 1
A² - B² = -16x + 8

Answer 2

vamos lá...

$A=2x-3~~~~e~~~~B=2x+1 \\ \\ A^2-B^2= \\ \\ (2x-3)^2-(2x+1)^2= \\ \\ 4x^2-12x+9-(4x^2+4x+1)= \\ \\ \not4x^2-12x+9-\not4x^2-4x-1= \\ \\ -12x-4x+9-1= \\ \\ -16x+8 \\ \\ Letra~~C$

Calculando:
(2x-3)²=(2x-3)(2x-3)=4x²-6x-6x+9=4x²-12x+9

(2x+1)²=(2x+1)(2x+1)=4x²+2x+2x+1=4x²+4x+1