10

Set 14: Systems of Equations (Intermediate)

Explanation

Answer: C

Solve by elimination (you may need to multiply one equation): {3x+2y=16x+y=6\begin{cases} 3x + 2y = 16 \\ x + y = 6 \end{cases}

A.

(3,3)(3, 3)

B.

(5,1)(5, 1)

C.

(4,2)(4, 2)

✓ Correct
D.

(2,4)(2, 4)

Detailed Explanation

Choice C is correct. Choice C is the correct answer. To eliminate a variable, we need matching coefficients. Step 1: Multiply the second equation by 2: 2(x + y) = 2(6)$2x + 2 y = 12$$$ Step 2: Subtract from the first equation: (3 x + 2 y) - (2 x + 2 y) = 16 - 12x = 4 Step 3: Substitute $x = 4$ into the second equation: $$$4+ y = 6$y = 2 Solution: (4,2)(4, 2) Verification: 3(4)+2(2)=12+4=163(4) + 2(2) = 12 + 4 = 16 ✓ Strategic Tip: Multiply equations to create matching or opposite coefficients for elimination. Choice A is incorrect because 3(3)+2(3)=9+6=15163(3) + 2(3) = 9 + 6 = 15 \neq 16. Choice B is incorrect because 3(5)+2(1)=15+2=17163(5) + 2(1) = 15 + 2 = 17 \neq 16. Choice D is incorrect because 3(2)+2(4)=6+8=14163(2) + 2(4) = 6 + 8 = 14 \neq 16.

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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