решите уравнение -(3х-1)^2+2(5+х)*(х-5)+7х^2=3

Question

решите уравнение -(3х-1)^2+2(5+х)*(х-5)+7х^2=3

Answer 1

-(3x-1)^2+2(5+x)*(x-5)+7x^2=3
-(9x^2-6x+1)+2*(5+x)*(x-5)+7x^2-3=0
-9x^2+6x-1+2*(5+x)*(x-5)+7x^2-3=0

-9x^2+6x-1+(10+2x)*(x-5)+7x^2-3=0

-9x^2+6x-1+(-50+2x^2)+7x^2-3=0

-9x^2+6x-1-50+2x^2+7x^2-3=0

-9x^2+6x-51+2x^2+7x^2-3=0

-7x^2+6x-51+7x^2-3=0

6x-51-3=0

6x-54=0

x=54/6
x=9

Answer 2

-(3х-1)^2+2(5+х)*(х-5)+7х^2=3

-(9x^2-6x+1)+2x^2-50+7x^2-3=0

-9x^2+6x-1+9x^2-53=0

6x=54

x=9