Question

Afla numarul necunoscut in fiecare expresie numerica
450-12*a=330
1000-a:5=965
a+6-14*19=500
(320+a)*3*5=7500

Answer 1

1)450-12×a=330=>12×a=450-330
=>12×a=120=>a=120÷12=>a=10
2)1000-a÷5=965=>a÷5=1000-965
=>a÷5=35=>a=35÷5=>a=7
3)a+6-14×19=500=>a+6-266=500
=>a+6=500+266=>a+6=766=>a=766-6
=>a=760
4)(320+a)×3×5=7500=>(320+a)×3=7500
÷5=>(320+a)×3=1500=>320+a=1500÷3
=>320+a=500=>a=500-320=>a=180
Sper ca team ajutat