Исключим переменную x1 из всех урав

Исключим переменную x1 из всех уравнений, кроме первого. Это эквивалентно получению нулей во 2-й и 3-ей строке первого столбца.
Для этого умножим первое уравнение на (-2) и (-3) и сложим соответственно, со 2-м и 3-м уравнением:

Результаты (английский) 1:

Delete the variable x 1 from all equations, except the first. This is equivalent to getting the zeros in 2-nd and 3-rd line of the first column.To do this, multiply the first equation by ( -2) and ( -3) and add respectively, with 2 and 3-m equation:

Результаты (английский) 2:

Eliminate the variable x1 from all equations, except the first. This is equivalent to the production of zeros in the 2nd and 3rd row of the first column.
To do this, multiply the first equation by (-2) and (-3) and add, respectively, with the 2nd and 3rd equation:

Результаты (английский) 3:

we x1 variable from all equations except the first. this is equivalent to zeros in the 2nd and 3rd line of the first column.for this we first equation (2) and (3) and lay down, respectively, with the 2nd and 3rd equation: