4(х+3)+5(х-3)=105 уравнение
4x + 12 + 5x - 15 = 105 9x - 3 = 105 9x = 108 x = 108/9 = 12
4(х+3)+5(х-3)=105 4х+12+5х-15=105 9х-3=105 9х=105+3 9х=108 х=12