Решите уравнение x(x-6)+20x^2=7x-2

Question

Решите уравнение x(x-6)+20x^2=7x-2

Answer 1

x(x-6)+20x^2=7x-2

x^2-6x+20x^2=7x-2

21x^2-6x-7x+2=0

21x^2-13x+2=0

D=b^2-4ac=169-4*21*2=1

x1=(13+1)/(21*2)=14/42=1/3

x2=(13-1)(21*2)=12/42=6/21=2/7

Answer 2

x(x-6)+20x^2=7x-2

21x^2-13x+2=0

D=(-13)^2-4*21*2=169-168=1

x1=(1-(-13))/(2*21)=1/3
x2=(-1-(-13))/(2*21)=2/7