Question

a+b=80
a=a:2+bx2
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Care sunt nr?

Answer 1

a+b=80    a=80-b
a=a:2+bx2      80-b=(80-b)/2+2b      -b-2b+b/2=-80+40
-3b+b/2=-40
-5b/2=-40
-b=-40*2:5=-80:5=-16
b=16
a=80-16=64
a=64

Answer 2

A+B=80 A=A/2+2b. => A+B=80 A-A/2=2B => A+B=80 | x2 A/2-2B=0 => 2A+2B=-160 A/2-2B=0 => 2A+A/2=160 => 5A/2=160 => 5A=80 => A=16 A=16 B=A-80 => B=64 (Pune tu unde trebuie paranteza de modul)