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Set 1: Systems of Equations

Explanation

Answer: C

Solve by elimination: {3x+2y=163x2y=8\begin{cases} 3x + 2y = 16 \\ 3x - 2y = 8 \end{cases}

A.

(3,3.5)(3, 3.5)

B.

(5,0.5)(5, 0.5)

C.

(4,2)(4, 2)

✓ Correct
D.

(2,5)(2, 5)

Detailed Explanation

Choice C is correct. Choice C is the correct answer. The 2y2y terms are opposites, so we add the equations. Step 1: Add the equations: (3 x + 2 y) + (3 x - 2 y) = 16 + 8$6x = 24$x = 4 Step 2: Substitute x=4x = 4 into the first equation: 3(4) + 2 y = 16$12+ 2 y = 162y = 4y = 2$$ Solution: (4, 2)Verification:Verification:3(4) - 2(2) = 12 - 4 = 8StrategicTip:Oppositecoefficientssignalthatadditionistherightmove.ChoiceAisincorrectbecause✓ Strategic Tip: Opposite coefficients signal that addition is the right move. Choice A is incorrect because3(3) + 2(3.5) = 9 + 7 = 16,but✓, but3(3) - 2(3.5) = 9 - 7 = 2 \neq 8.ChoiceBisincorrectbecause. Choice B is incorrect because 3(5) - 2(0.5) = 15 - 1 = 14 \neq 8.ChoiceDisincorrectbecause. Choice D is incorrect because 3(2) + 2(5) = 6 + 10 = 16,but✓, but3(2) - 2(5) = 6 - 10 = -4 \neq 8$.

Key Steps:

The correct answer is (4,2)(4, 2)

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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