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SorySorana7
a fost răspuns

Se stie ca a+b+c =7 Calculati :
a). 2a+2b+2c
b).10a+10b+10c
c).a x(este ori) 13+bx13+cx13 +21
d).8a+8b+8c-12
e). 400-(5a+5b+5c)
f). 6a+6b+6c+100
Va rog rapid!!

Răspuns :

Flafly16
a) 2a+2b+2c=
=2•(a+b+c)
=2•7
=14

b)10a+10b+10c=
=10•(a+b+c)
=10•7
=70

c)a•13+b•13+b•13+21=
=13•(a+b+c)+21
=13•7+21
=91+21
=102

d)8a+8b+8c-12=
=8•(a+b+c)-12
=8•7-12
=56-12
=44

e)400-(5a+5b+5c)=
=400-[5•(a+b+c)]
=400-(5•7)
=400-35
=365

f)6a+6b+6c+100=
=6•(a+b+c)+100
=6•7+100
=30+100
=130