Question

б)х^2+20x+91=0
в)7х^-9x+2=0

Answer 1

Б) d=400-364
D= 36
X1=-20+6/2
X1=-7
X2=-20-6/2
X2=-13
В) d=81-56
D=25
X1=9+5/14
X1=1
X2=9-5/14
X2=2/7