3x + 4 ( 15 – 5x ) = 26
3x + 60 – 20x = 26
– 20x + 3x = 26 – 60
– 17x = – 34
x = 2
Тогда у = 15 – 5 × 2 = 15 – 10 = 5
(2; 5)
