Решите уравнение 1) + = 9 2) - = 7 3) + =19
1) 4x + 5x = 90 9x = 90 x = 10 2) 8x - x = 70 7x = 70 x = 10 3) 4x + 15x = 114 19x = 114 x = 6 Удачи!