№235
1)
6х²-5х+1 = 6 (x²- 5/6x+ 1/6)= 6 (x² - 3/6 -2/6 + 1/6 )=
= 6 (x² - 1/3x -1/2x - (1/3) *(-1/2) )= 6 ( x (x-1/3) - 1/2 (x-1/3))=
= 6 (x-1/3)* (x-1/2)
3)
12x²+5x-2= 12 ( x² +5/12 x - 2/12) = 12( x²+ 8/12 x - 3/12 x - 1/6)=
= 12 (x²+ 2/3x - 1/4x - 1/4 * 2/3 ) =
= 12 ( x (x+2/3) - 1/4 (x+2/3) )= 12 (x+2/3)(x-1/4)
№236
1)
-15х²+2х+1= 15 (-х²+2/15х+1/15) = -15 (х²-2/15х-1/15) =
= -15 (х²- 1/3х +1/5х + 1/5 *(-1/3) ) =
= -15 (х (х-1/3) +1/5 (х-1/3))= -15 (х-1/3)(х+1/5)
3)
-16х²+8х+3= -16 (х²-8/16 х³ -3/16) =
= -16 ( х² - 12/16 х +4/16х - 3/16)=
= -16 ( х²- 3/4 х + 1/4х + 1/4 * (-3/4) )=
= -16 (х (х-3/4)+ 1/4 (х-3/4))=
= -16 (х-3/4)(х+1/4)