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2010-01-19T19:57:56+01:00
A3=a1+2r
a5=a1+4r

a1+2r+a1+4r=24
(a1+2r)*(a1+4r)=135

2a1+6r=24 /:2
(a1+2r)*(a1+4r)=135

a1+3r=12
(a1+2r)*(a1+4r)=135

a1=12-3r
(12-3r+2r)*(12-3r+4r)=135

(12-r)*(12+r)=135
144+12r-12r-r^2=135 (^2- do kwadratu)
144-r^2=135
-r^2=135-144
-r^2=-9 /:(-1)
r^2=9
r=-3 i r=3
gdy r=-3
a1=12-3r
a1=12-3*(-3)
a1=12+9
a1=21

gdy r=3
a1=12-3r
a1=12-3*3
a1=12-9
a1=3
1 5 1