(x-4)(x+2)-2()3x+1)(x-3)=x(x+27)

Question

(x-4)(x+2)-2()3x+1)(x-3)=x(x+27)

Answer 1

( Х - 4 )( Х + 2 ) - 2( 3х + 1 )( Х - 3 ) = х( Х + 27 )
Х^2 + 2х - 4х - 8 - 2( 3х^2 - 9х + Х - 3 ) = х^2 + 27х
Х^2 - 2х - 8 - 2( 3х^2 - 8х - 3 ) = х^2 + 27х
Х^2 - 2х - 8 - 6х^2 + 16х + 6 = х^2 + 27х
- 5х^2 + 14х - 2 = х^2 + 27х
6х^2 + 13х + 2 = 0
D = 169 - 48 = 121 = 11^2
X1 = ( - 13 + 11 ) : 12 = - 2/12 = - 1/6
X2 = ( - 13 - 11 ) : 12 = - 24 : 12 = - 2
Ответ ( - 2 ) ; ( - 1/6 )

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Answer 2

(x-4)(x+2)-2()3x+1)(x-3)=x(x+27)
(x^2+2x-4x-8) - (6x+2)(x-3)= x^2+27x
(x^2-2x-8) - (6x^2-18x+2x-6)= x^2 +27x
x^2-2x-8 -6x^2+18x-2x+6 = x^2 +27x
x^2-2x-6x^2+18x-2x -x^2-27x= -6+8
-6x^2 -13x= 2
-6x^2-13x-2=0   \*(-1)
6x^2+13x+2=0
D= b^2-4ac= 13^2- 4*6*2= 169- 48= 121
x1,2= (-b +- (корень из)D) / 2*a
x1,2= (-13+-11)/ 12
x1= -2/12= -1/6
x2= -24/12= -2

Ответ: x1= -1/6
x2= -2

Comments

дякую:)