The given system of equations is:

$-10x + y = 64$

$-10x + 5y = 40$

To eliminate a variable, we analyze the coefficients:

• The $x$-terms have the same coefficient (-10). Subtracting the equations will eliminate $x$.
• The $y$-terms have different coefficients (1 and 5), so adding or subtracting will not directly eliminate $y$.

First Step:

Subtract the first equation from the second:

$(-10x + 5y) - (-10x + y) = 40 - 64$

$-10x + 5y + 10x - y = -24$

$4y = -24$

Thus, the correct choice is:

✅ Subtract to eliminate $x$.

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Would you like a step-by-step solution for the whole system?

Related Questions:

1. What happens if we try to eliminate $y$ instead?
2. How can we solve the system using substitution?
3. What is the graphical interpretation of this system?
4. How do we solve this system using matrices?
5. Can we solve this system using determinants (Cramer's Rule)?

Tip:

When choosing elimination, align like terms and look for matching coefficients to add or subtract easily. 🚀