X1+x2=3 U x1*x2=-10
1/x1+1/x2=(x2+x1)/(x1x2)=-3/10=-0,3
x1/x2+x2/x1=(x1²+x2²)/(x1+x2)=[(x1+x2)²-2x1x2]/(x1x2)=
=(9+20)/(-10)=-2,9
1)
а)3(х-4)=-5(х+2)
3х-12=-5х-10
3х+5х=12-10
8х=2/:8
х=0,25
б)1-2(х-2)=х-(4х+5)
1-2х+4=х-4х-5
-2х-х+4х=-4-5-1
х=-10
в)х+3/16=1/4 /:16
х+3=4
х+3=4
х=4-3
х=1
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