Verified answer

[tex]4x + 7 = 5(x - t) \\ 3(x + 6t) - 9t = 15 \\ \\ 4x + 7 = 5x - 5t \\ 3x + 18t - 9t = 15 \\ \\ x = 5t + 7 \\ 3(5t + 7) + 9t = 15 \\ 15t + 21 + 9t = 15 \\ 24t = 15 - 21 \\ 24t = - 6 \\ t = - \frac{1}{4} \\ \\ x = 5 \times ( - \frac{1}{4} ) + 7 = \\ - 1 \frac{1}{4 } + 6 \frac{4}{4} = 5 \frac{3}{4} [/tex]

Ответ: х = 5 3/4 ; t = - 1/4