(19x-10)^2 <=(7x-18)^2

(19x-10)²<=(7x-18)²
361x²-380x+100<=49x²-252x+324
361x²-49x²-380x+252x+100-324<=0
312x²-128x-224<=0 |:6
39x²-16x-28<=0
D=256+4368=4624
x1=16+68/78=84/78=42/39
x2=16-68/78=-52/78=-26/39=-2/3

xc[-2/3;42/39]