Respuesta :
⇒x²+ 4² - x²+ 2x - 2x + 4 = 20
⇒ x² - x² + 2x - 2x + 4² + 4 = 20
⇒ 16 + 4 = 20
⇒ 20 = 20
RHS = LHS hence proved
Answered by Gauthmath must click thanks and mark brainliest
Answer:
x = 0
Step-by-step explanation:
(a + b)² = a² +2ab + b²
(a +b)(a -b)= a² - b²
(x + 4)² - (x + 2 )(x - 2) = 20
x² + 2*4 *x + 4² - [x² - 2²] = 20
x² + 8x + 16 - [x² - 4] = 20
x² + 8x + 16 - x² + 4 = 20 {(-1) is distributed x² and (-4)²}
x² - x² + 8x + 16 + 4 = 20 {Combine like terms}
8x + 20 = 20
8x = 20 - 20
8x = 0
x = 0