Question

(x+2)² +2(x+5)(x-5)= 3(x-1)²+1
Solutia ecuatiei este ?

Answer 1

$\displaystyle (x+2)^2+2(x+5)(x-5)=3(x-1)^2+1 \\ x^2+2 \cdot x \cdot 2+2^2+2(x^2-25)=3(x^2-2 \cdot x \cdot 1 +1^2)+1 \\ x^2+4x+4+2x^2-50=3(x^2-2x+1)+1 \\ x^2+4x+4+2x^2-50=3x^2-6x+3+1 \\ x^2+2x^2-3x^2+4x+6x=3+1-4+50 \\ 10x=50 \\ x= \frac{50}{10} \\ x=5$