A)D=b^2-4ac=16-(-84)=100 k=
=10
x1=(-k+
)/a=(-10+
)/1=-10+
=-10+11=1
x2=(-k)/a=(-10-)/1=-10-=-10-11=-21
b)D=16+84=100 k=10
x1=(-10+)/7=(-10)/7=(-10-11)/7=-3
x2=(-10-)/7=(-10-)/7=(-10+11)/7=1/7
c)D=4+8=12 k=
x1=
x2=)/2](https://tex.z-dn.net/?f=%28-%5Csqrt%7B12%7D+%2B%5Csqrt%7B+%5Csqrt%7B12%7D+%2B2%7D+%29%2F2%3D%28-2+%5Csqrt%7B3%7D+%2B%5Csqrt%7B2+%5Csqrt%7B3%7D+%2B2%7D+%29%2F2%3D%5Btex%5D%28-2+%5Csqrt%7B3%7D+-+%5Csqrt%7B2%28+%5Csqrt%7B3%7D%2B1+%7D+%29%29%2F2)
/
x1=(-k+
x2=(-k
b)D=16+84=100 k=10
x1=(-10+
x2=(-10-
c)D=4+8=12 k=
x1=
x2=
/