Question

x2 + 2x - 3(x-1) = 28:
Ayúdenme plox

Answer 1

Respuesta:

Explicación paso a paso:

Asumiendo que quisiste decir x^2 +2x -3(x-1) = 28 entonces:

x^2 +2x -3(x-1) = 28

x^2 +2x -3x +3 = 28

x^2 -x = 28-3 = 25

Completando cuadrados :

x^2 + 2*(-1/2)*x + (-1/2)^2 - (-1/2)^2 = 25

( x^2 +2*(-1/2)*x + (-1/2)^2 ) -1/4 = 25

(x - 1/2)^2 = 25 + 1/4 = 100/4 + 1/4 = 101/4

x - 1 /2 = + - sqr(101/4)

x1 = 1/2 + sqr(101/4) =~ 1/2 + 5 = 5.5  ;   x2 = 1/2 - sqr(101/4) =~ 1/2 - 5 = -4.5