Question

Rezovati in multimea numerelor naturale ecuatia:
3×{10+2×[40-2×(28-3×5)]}-7x=51

Answer 1

3*{10+2*[40-2*(28-3*5)]}-7x=51
3*{10+2*[40-2*(28-15)]}-7x=51
3*[10+2*(40-2*13)]-7x=51
3*[10+2*(40-26)]-7x=51
3*(10+2*14)-7x=51
3*(10+28)-7x=51
3*38-7x=51
114-7x=51
7x=114-51
7x=63
x=63:7
x=9