объяснение:
x(5-x)=15
5x-x^2=15
x^2-5x+15=0
d=25-60=-35
x1=(5-sqrt(-35))/2 = (5-isqrt(35))/2=5/2-1/2sqrt(35)i
x2=(5+sqrt(-35))/2 = (5+isqrt(35))/2=5/2+1/2sqrt(35)i
объяснение:
x(5-x)=15
5x-x^2=15
x^2-5x+15=0
d=25-60=-35
x1=(5-sqrt(-35))/2 = (5-isqrt(35))/2=5/2-1/2sqrt(35)i
x2=(5+sqrt(-35))/2 = (5+isqrt(35))/2=5/2+1/2sqrt(35)i