4

Set 8: Systems of Equations (Advanced)

Explanation

Answer: C

Is the point (6,3)(6, 3) a solution to the system? {x2y=03x+y=21\begin{cases} x - 2y = 0 \\ 3x + y = 21 \end{cases}

A.

Only for the first equation

B.

Cannot be determined

C.

Yes

✓ Correct
D.

No

Detailed Explanation

Choice C is correct. Choice C is the correct answer. To verify if (6,3)(6, 3) is a solution, we substitute x=6x = 6 and y=3y = 3 into both equations. First equation: x2y=0x - 2 y = 0 62(3)=66=06- 2(3) = 6 - 6 = 0 ✓ (True) Second equation: 3x+y=213(6)+3=18+3=213x + y = 213(6) + 3 = 18 + 3 = 21 ✓ (True) Since the point satisfies both equations, it is a solution to the system. Strategic Tip: A point is only a solution if it works for ALL equations in the system. Choice A is incorrect because the point satisfies both equations, not just the first one. Choice B is incorrect because we can always determine if a point is a solution through substitution. Choice D is incorrect because the point does satisfy both equations.

Key Steps:

The correct answer is Yes

Why others are wrong:
A: Choice A is incorrect and may result from a calculation error.
B: Choice B is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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