Răspuns :
a/5 + 3a/5 = 4a/5
x/7 + 3 - x/7 = 3 (se simplifica x/7 cu - x/7)
x + 2/x + x - 1/x = 2x + 1/x = 2x²/x + 1/x = 2x² + 1/x
x/7 + 3 - x/7 = 3 (se simplifica x/7 cu - x/7)
x + 2/x + x - 1/x = 2x + 1/x = 2x²/x + 1/x = 2x² + 1/x