(51/10)x^2-(119/10)x+17/5
=(51/10)[x^2-(119/10)(10/51)x+(17/5)(10/51)]
=(51/10)[x^2-119x/51+34/51]
=(51/10)[x^2-119x/51+(119/102)²-14161/10404+6936/10404]
=(51/10)[(x-119/102)²-7225/10404]
=(51/10)[(x-119/102)²-(85/102)²]
=(51/10)(x-119/102-85/102)(x-119/102+85/102)
=(51/10)(x-204/102)(x-34/102)
=(51/10)(x-2)(x-1/3)
=(x-2)(51x/10-17/10)