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Verified answer

[tex]\\\left \{ {{x + y = 7.5} \atop {x = 4y}} \right. \\ \\\left \{ {{4y + y = 7.5} \atop {x = 4y}} \right. \\ \\ 5y = 7.5 \\ y = 7.5 \div 5 \\ y = 1.5 \\ \\ x = 4 \times 1.5 \\ x = 6[/tex]

Ответ: 1,5 и 6