Suat Ayöz · 29d

The error comes when one equates (x–7)₂²= (25–3x)² When squared, these are equal for x=79/9. But (x–7)₂ = ⁴/₃ for x=79/9 and 25–3x = –⁴/₃ for x=79/9 So, they are not in fact equal. 79/9 is a bogus root that comes about. 25–3x is negative, so it cannot be the square root of a real number.