12. The sum of the numerator and denominator of a certain positive fraction is 11. If 1 is added to - id2115670120211218 от galimullinaan 18.12.2021 19:26

Question

Алгебра: 12. The sum of the numerator and denominator of a certain positive fraction is 11. If 1 is added to both the numerator and the denominator, the fraction is increased by 3/56. Find the fraction.

galimullinaan · Accepted Answer

а) (х² – х)²+ х² – х = 6; Замена переменной х²-х=t получаем уравнение t²+t=6 t²+t-6=0 D=1+24=25 t=(-1-5)/2 = -3      или      t=(-1+5)/2 = 2 Возвращаемся к переменной х:  х²-х=-3    или х²-х=2 решаем ещё два квадратных уравнения х²-х+3 = 0     D=1-12 0 уравнение не имеет корней  и  х²-х-2=0   D=1+8=9    х = -1    или  х = 2 ответ. -1;2 б) (3х² + 2х)² – 4(3х² + 2х) – 5 = 0; Замена    (3х²+2х)=t t²-4t-5=0 D=16+20=36 t=(4-6)/2 = -1      или      t=(4+6)/2 = 5 Возвращаемся к переменной х:  3х² + 2х...

12. The sum of the numerator and denominator of a certain positive fraction is 11. If 1 is added to both the numerator and the denominator, the fraction is increased by 3/56. Find the fraction.

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