task/28556417-------------------2.2x² -3x+1 = 2x² -2x- x +1 =(2x² -2x ) - (x -1)= 2x(x -1) -(x-1) =(x-1)(2x-1) =2(x-1)(x-1/2) .* * * ax²+bx +c=a(x-x₁)(x-x₂) * * *2x² -3x+1 =0 ; D =3² -4*2*1 =1 =1²;x₁ =(3 +1)/(2*2) = 1 ;x₂ =(3 -1)/4 =1/2 .2x² -3x+1 =2(x-x₁)(x-x₂)=2(x-1)(x-1/2) . -------------------4.7x² -3x -22 = 7x² -14x +11x -22 =7x(x-2) +11(x-2) = (x-2)(7x+11)=7(x-2)(x+11/7) .---7x² -3x -22 = 0 D =3² -4*7*(-22) =9 +616 =625 =25²x₁ =(3 +25)/(2*7) = 2 ;x₂ =(3 -25)/14 = -11/7 .7x² -3x -22 =7(x-x₁)(x-x₂)=7(x-2)(x+11/7) . -------------------12.7x² +3x -22 =7x² +14x -11x -22 =7x(x+2) -11(x+2) = (x+2)(7x-11)=7(x+2)(x-11/7).7x² +3x -22 = 0 см упр 4 x₁ =(-3 -25)/14 = -2 ;x₂ =(-3 +25)/(2*7) = 11/7 .7x² +3x -22 =7(x+2)(x-11/7).-------------------18.x² - 4x +4 =(x -2)² = (x-2)(x-2) .---x² - 4x +4 =0 D₁=2² -4 =0 * * * D = 4² -4*1*4 =0 x₁=x₂ =2 +0 =2 x² - 4x +4 =(x-x₁)(x-x₂)=(x-2)(x-2) .-------------------20.x² - 6x +9 = (x-3)² = (x-3)(x-3) . * * * x² - 3x -3x +9 =x(x-3) -3(x-3) =(x-3)(x-3) * * *---x² - 6x +9 = 0 D =6² -4*1*9 =0 * * * D₁=(6/3)² -9 =9 -9 =0 * * * x₁=x₂ =3 +0 =3 .x² - 6x +9 =(x-x₁)(x-x₂) = (x-3)(x-3) .-------------------22.-x²+2x +3 =- (x² -2x -3 ) = - (x² -3x +x -3 ) = -( x(x-3) +(x-3)) = -(x-3)(x+1). ----x²+2x +3 = 0 ; D =2² -4*(-1)*3 =16 = 4² x₁ =(-2 -4)/2*(-1) = 3 .x₂ =(-2 +4)/(-2) = - 1.-x²+2x +3 = -1(x -3) (x -(-1) ) =- (x-3)(x+1) . * * * (3-x)(x+1) * * *