Решите уравнения а)(х-1)^2(х+2)=0 б)х^2-1)(x-3)=0 d)(x-4)^2(x-3)=0 u) (x^2-4)(x+1)=0

Question

Алгебра: Решите уравнения а)(х-1)^2(х+2)=0 б)х^2-1)(x-3)=0 d)(x-4)^2(x-3)=0 u) (x^2-4)(x+1)=0

жека12рус · Accepted Answer

X^2 - 4x + 3 = 0 ; D= (-4)^2 - 4 * 1 * 3 = 16 - 12 = 4 ; Sqrt(4) = 2 ; x' = (- (-4) + 2)/ 2 * 1 = (4 + 2) / 2 = 6 / 2 = 3 ; x" = (- (- 4) - 2) / 2 * 1 = (4 - 2) / 2 = 2 /2 = 1
2) 2x^2 - 50 = 0 ; 2x^2 = 50 ; x^2 = 25 ; x = Sqrt(25) = +- 5
3) x^2 - 5x = 0 ; D = (- 5) ^ - 4 * 1 * 0 = 25 - 0 = 25 ; Sqrt(25) = 5
x' = (- (-5) + 5) / 2 * 1 = (5 + 5 )/ 2 = 10 / 2 = 5 ; x" = (-(- 5) - 5) / 2 * 1 = 0
4) (x - 3) / (x - 1) = 0 ; x - 3 = 0 ; x = 3
5) 4 * (9 - 5x) + 7x = 11 - 2(8x + 1) ; 36 - 20x + 7x = 11 - 16x - 2 ;
16x - 20x + 7x = 11 - 2 - 36 ; 3x = - 27 ; x = - 27 / 3 ; x = - 9

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