Question

oblicz układ równan (obicz ia i b)

b-a=a-2

9/b=b\a (9\b i b\ a to ułamek)

Answer 1

b - a = a - 2

9 / b = b/a

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b = 2a - 2

b^2 = 9*a

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b = 2 a - 2

( 2 a - 2)^2 = 9 a

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4 a^2 - 8 a + 4 = 9a

4 a^2 - 17 a + 4 = 0

delta = ( -17)^2 - 4*4*4 = 289 - 64 =225

p(delty) = 15

a = [ 17 - 15]/8 = 2/8 = 1/4

lub

a = [ 17 + 15]/8 = 32/8 = 4

zatem

b = 2*(1/4) - 2 = 1/2 - 2 = - 1  1/2

lub

b = 2*4 - 2 = 8 - 2 = 6

Odp. a = 1/4 ,  b = -  3/2      lub  a = 4, b = 6

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