Gleichungen lösen, binomische Formeln. (x + 2 )^2 - (x - 4 )^2 = 2(x - 4)+ 9x

Question

(x + 2 )^2 - (x - 4 )^2 = 2(x - 4)+ 9x 

Answer 1

(x + 2)^2 - (x - 4)^2 = 2(x - 4) + 9x

x^2 + 4x + 4 - (x^2 - 8x + 16) = 2x - 8 + 9x

x^2 + 4x + 4 - x^2 + 8x - 16 = 2x - 8 + 9x

12x - 12 = 11x - 8

x = 4

Answer 2

Die Probe bestätigt die Lösung.