6

Set 1: Systems of Equations (Intermediate)

Explanation

Answer: B

Solve: {5x+3y=292xy=5\begin{cases} 5x + 3y = 29 \\ 2x - y = 5 \end{cases}

A.

(7,2)(7, -2)

B.

(4,3)(4, 3)

✓ Correct
C.

(5,43)(5, \frac{4}{3})

D.

(3,143)(3, \frac{14}{3})

Detailed Explanation

Choice B is correct. Choice B is the correct answer. Multiply second equation by 3 and add to first. Step 1: Multiply second by 3: 6x3y=156x - 3 y = 15 Step 2: Add to first: (5 x + 3 y) + (6 x - 3 y) = 29 + 15$11x = 44$x = 4 Step 3: Substitute: 2(4)y=5y=32(4) - y = 5 \Rightarrow y = 3 Solution: (4,3)(4, 3) Verification: 5(4)+3(3)=295(4) + 3(3) = 29 ✓ and 2(4)3=52(4) - 3 = 5 ✓ Strategic Tip: Multiplying by 3 creates 3y-3 y to cancel +3y+3 y. Choice A is incorrect because 2(7)(2)=1652(7) - (-2) = 16 \neq 5. Choice C is incorrect because 5(5)+3(43)=295(5) + 3(\frac{4}{3}) = 29 ✓, but 2(5)4352(5) - \frac{4}{3} \neq 5. Choice D is incorrect because 5(3)+3(143)=295(3) + 3(\frac{14}{3}) = 29 ✓, but 2(3)14352(3) - \frac{14}{3} \neq 5.

Key Steps:

The correct answer is (4,3)(4, 3)

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