3. Упростите выражения. a) 12x + 23y + 16x + 18y б) 34x + 43y + 11x – 5y в) (12x + 14y) – (8x + 9y) г) (42x + 8y) – (15x – 4y)

Решение:

• a) \(12x + 23y + 16x + 18y = (12x + 16x) + (23y + 18y) = 28x + 41y\)
• б) \(34x + 43y + 11x - 5y = (34x + 11x) + (43y - 5y) = 45x + 38y\)
• в) \((12x + 14y) - (8x + 9y) = 12x + 14y - 8x - 9y = (12x - 8x) + (14y - 9y) = 4x + 5y\)
• г) \((42x + 8y) - (15x - 4y) = 42x + 8y - 15x + 4y = (42x - 15x) + (8y + 4y) = 27x + 12y\)

Ответ: a) 28x + 41y; б) 45x + 38y; в) 4x + 5y; г) 27x + 12y.