Question

(6x-1)(1+6x)+14<7x(2+5x)

Answer 1

6x+36x^2-1-6x+14<14x+35x^2

36x^2-35x^2-14x+13<0

x^2-14x+13<0

D=196-52=144

x1=(14+12)/2*1=26/2=13

x2=(14-12)/2*1=2/2=1

(1;13)