В приложении ..........
x^4-50x^2+49=0
x^2=t
t^2-50t+49=0
По теореме Виета
t1+t2=-(-50)=50
t1*t2=49
t1=1
t2=49
x^2=t1
x^2=t2
x^2=1
x1=1
x2=-1
x^2=49
x3=7
x4=-7
