(a-x)(a+x)-b(b+2)-(a-b-x)(a+b+x)=0

(a-x)(a+x)-b(b+2)-(a-b-x)(a+b+x)=0

a²-x²-b²-2b-a²+b²+x²=0

-2b=0

b=0

(a-x)(a+x)-b(b+2)-(a-b-x)(a+b+x)=0

а²-х²-b×(b+2) - (a-b-x)×(a+b+x)

a²-x²-b²-2b- (a-b-x)× (a+b+x)

a²-x²-b²-2b-( a²-(-b-x)²)

a²-x²-b²- 2b- (a²-( - ( b+x))²)

a²-x²-b²-2b- (a²-( b+x)²)

a²-x²- b²- 2b- a²+(b+x)²

-x²-b²- 2b+ (b+x)²

-x²-b²-2b+ b²+2bx+x²

-b²- 2b+b²+2bx

-2b+2bx

ответ будеть: -2b+2bx