{[7*(2*a+3)+3*(2*a+3)]×12}+160=1000

Răspuns :

Răspuns:

{[7*(2*a+3)+3*(2*a+3)]×12}+160=1000

[7·(2a+3)+3·(2a+3)]·12=1000-160

14a+21+6a+9=840:12

20a+30=70

20a=70-30

a=40:20

a=2