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Equation A: x + z = 6 Equation B: 3x + 2z = 1 Which of the following is a possible step in eliminating the z-term?
a. Multiply equation A by -2.
b. Multiply equation B by 2.
c. Multiply equation A by 3.
d. Mulitply equation B by 3.

Respuesta :

naǫ
To eliminate a term, its coefficients in both equations must be opposite numbers.

[tex]x+z=6 \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ |\times (-2) \\ 3x+2z=1 \\ \\ -2x-2z=-12 \\ \underline{3x+2z=1 \ \ \ \ \ \ \ \ } \\ x=-11 \\ \\ x+z=6 \\ -11+z=6 \\ z=6+11 \\ z=17 \\ \\ (x,y)=(-11,17)[/tex]

The answer is A. multiply equation A by -2.

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