Question

Rezolvati ca pt clasa 1 !

1)a+a-72+50=58
a=?
2)a+a+a+40-50=50
a=?
3)a-b=30
a+(a+b)=90
a=?
b=?

Answer 1

1)a+a-72+50=58 A+a=58-50+72=80 resulta can a=80:2=40 2)a+a+a+40-50=50 3xa=50+50-40=60 A=60:3=20 3)a-b=30 A+(a+b)=90 A=30+b 30+b+(30+b+b)=90 3xb=90-30-30=30 B=30:3=10 A=30+b=30+10=40

Answer 2

1) a+a-72+50=58 => a+a=58-50+72 => 2a=80 => a=80/2 => a=40 2) a+a+a+40-50=50 => 3a=60 => a=60/3 => a=20 3)a-b=30 ; a+(a+b)=90 »il scoatem pe b din prima relatie si il inlocuim in a doua« -b=30-a => b=a-30 »si inlocuim« a+(a+a-30)=90 => a+a+a-30=90 => 3a= 90+30 => a=120/3 => a =40 deci b=a-30 din relatia de mai sus, adica b=40-30 => b=10.