Question

{[(3×a+5)×3+5]×3+5}×3+5=281 aflati termenul necunoscut

Answer 1

{[(3a+5)*3+5]*3+5}*3+5=281
{[9a+15+5]*3+5}*3+5=281
{[9a+20]*3+5}*3+5=281
{27a+60+5}*3+5=281
{27a+65}*3+5=281
81a+195+5=281
81a+200=281
81a=281-200
81a=81
a=1