Ответ:Решение:a) 5x + (3x - 7) = 9\( 5x + 3x - 7 = 9 \)\( 8x = 9 + 7 \)\( 8x = 16 \)\( x = 2 \)б) 3y - (5 - y) = 11\( 3y - 5 + y = 11 \)\( 4y = 11 + 5 \)\( 4y = 16 \)\( y = 4 \)Ответ: x = 2; y = 4.