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1500-6x[740-4x(65+15xa)]=780 repede va rog

Răspuns :

Explicație pas cu pas:

1500-6x[740-4x(65+15xa)]=780

6.[740-4.(65+15.a)]=1500-780=720

740-4.(65+15.a)=720:6=120

4.(65+15.a)=740-120=620

65+15.a=620:4=155

15.a=155-65=90

a=90:15

a=6