Question

(5+3x)² entre -3 =7


Despejar x

Answer 1

(5+3x)²/-3 = 7
(Multiplicamos todo por -3)

(5+3x)² = -21
25+30x+9x² = -21
9x²+30x+46 = 0

Usamos fórmula general

[-b±√(b²-4ac)]/2a
Siendo
a = 9
b = 30
c = 46
(Reenplazando)

[-30±√(900-1656)]/18
[-30±√-756]/18
[-30±2√-189]/18
[-15±√189i]/9

x1 = [-15+√189i]/9
x2 = [-15-√189i]/9

Son los dos posibles valores

Saludos Ariel