10

Set 17: Systems of Equations

Explanation

Answer: C

What is the intersection point of the lines y=3x4y = 3x - 4 and y=2x+6y = -2x + 6?

A.

(3,5)(3, 5)

B.

(1,1)(1, -1)

C.

(2,2)(2, 2)

✓ Correct
D.

(4,8)(4, 8)

Detailed Explanation

Choice C is correct. Choice C is the correct answer. To find the intersection, we set the two expressions for yy equal to each other. Step 1: Set the equations equal: 3x4=2x+63x - 4 = -2 x + 6 Step 2: Solve for xx: $$$3x + 2 x = 6 + 45x = 10$x = 2 Step 3: Find yy using either equation (using the first): y=3(2)4=64=2y = 3(2) - 4 = 6 - 4 = 2 Solution: (2,2)(2, 2) Verification: 2=2(2)+6=4+6=22= -2(2) + 6 = -4 + 6 = 2 ✓ Strategic Tip: The intersection point is where both lines have the same xx and yy values. Choice A is incorrect because 5=3(3)4=94=55= 3(3) - 4 = 9 - 4 = 5 ✓, but 52(3)+6=05\neq -2(3) + 6 = 0. Choice B is incorrect because 1=3(1)4=1-1 = 3(1) - 4 = -1 ✓, but 12(1)+6=4-1 \neq -2(1) + 6 = 4. Choice D is incorrect because 8=3(4)4=88= 3(4) - 4 = 8 ✓, but 82(4)+6=28\neq -2(4) + 6 = -2.

Key Steps:

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