Odpowiedzi

2009-12-12T21:44:54+01:00
A)

(3-x)(x+1) = 7-x(x+2)
3x-x²+3-x = 7-x²-2x
4x = 4
x = 1

b)

x²+4x = (x-1)(x+3)-1
x²+4x = x²+3x-x-3-1
2x = -4
x = -2

c)

(x-4)(x+1)+4(x+2) = x²-3
x²-4x+x-4+4x+8 = x²-3
x = -7

d)

x(2-x)+(x+2)(x-2) = 2
2x-x²+x²-4 = 2
2x = 6
x = 3