Первое не знаю
420 + (4 X + 360) = 940
4 X + 360 = 940 - 420
4 X + 360 = 520
4 X = 520 - 360
4 X = 160
X = 40
350 + (600 - 5 X) = 450
600 - 5 X = 450 - 350
600 - 5 X = 100
5 X = 600 - 100
5 X = 500
X = 100
Первое не знаю
420 + (4 X + 360) = 940
4 X + 360 = 940 - 420
4 X + 360 = 520
4 X = 520 - 360
4 X = 160
X = 40
350 + (600 - 5 X) = 450
600 - 5 X = 450 - 350
600 - 5 X = 100
5 X = 600 - 100
5 X = 500
X = 100