Выделив полный квадрат, разложите на множители.

1. 14+4x-x^2

2. 16-6x-x^2

3. - x^2+6x+7

1) 14+4x-x² = - (x²-4x-14) = - ((x-2) ²-18) = 18 - (x-2) ² = (2√3-x+2) (2√3+x-2)

2) 16-6x-x² = - (x²+6x-16) = - ((x+3) ²-25) = 25 - (x+3) ² = (5-x-3) (5+x+3) = (2-x) (8+x)

3) - x²+6x+7 = - (x²-6x-7) = - ((x-3) ²-16) = 16 - (x-3) ² = (4-x+3) (4+x-3) = (7-x) (1+x)