Решите уравнения: х+(90+30)=180,(х+90)+30=180,(х+60)*5=500,5*х+300=500

х+(90+30)=180 x + 120 = 180 x = 180 - 120 x = 60 60 + (90 + 30) = 180 180 = 180 (x + 90) + 30 = 180 x = 180 - 90 - 30 x = 60 (60 + 90) + 30 = 180 180 = 180  (x + 60) *5 = 500 5x + 300 = 500 5x = 500 - 300 5x = 200 x = 200 : 5 x = 40 (40 + 60) * 5 = 500 500 = 500 5*x + 300 = 500 5x + 300 = 500 5x = 500 - 300 5x = 200 x = 200 :5  x = 40 5 * 40 + 300 = 500 500=500