Răspuns:
[tex]((2 \times x - 15) \div 3) + 95 = 100 \\ (2 \times x - 15) \div 3 = 100 - 95 \\ (2 \times x - 15) \div 3 = 5 \\ 2 \times x - 15 = 5 \times 3 \\ 2 \times x - 15 = 15 \\ 2 \times x = 15 + 15 \\ 2 \times x = 30 \\ x = 30 \div 2 \\ x = 15[/tex]
notăm cu a- nr necunoscut
(a×2-15):3+95=100
(2a-15):3=100-95
(2a-15):3=5
2a-15=5×3
2a-15=15 => 2a=15+15=> 2a=30=> a=30:2=> a=15
