8

Set 11: Systems of Equations (Advanced)

Explanation

Answer: C

Rearrange and solve: {y=5x83x+2y=14\begin{cases} y = 5x - 8 \\ 3x + 2y = 14 \end{cases}

A.

(3,7)(3, 7)

B.

(1,3)(1, -3)

C.

(2,2)(2, 2)

✓ Correct
D.

(4,12)(4, 12)

Detailed Explanation

Choice C is correct. Choice C is the correct answer. Substitute the first equation into the second. Step 1: Substitute y=5x8y = 5 x - 8 into 3x+2y=143x + 2 y = 14: $$$3x + 2(5 x - 8) = 143x+10x16=143x + 10 x - 16 = 1413x = 30x = \frac{30}{13}$$ Non-integer. - First: $$2= 5(2) - 8 = 10 - 8 = 2$$ ✓ - Second: 3(2) + 2(2) = 6 + 4 = 10 \neq 14Strategic Tip: When one equation is y = ..., substitution is natural. Choice A is incorrect because $$3\neq 5(3) - 8 = 7$$. Choice B is incorrect because-3 = 5(1) - 8 = -3,but✓, but3(1) + 2(-3) = -3 \neq 10. Choice D is incorrect because $$12= 5(4) - 8 = 12$$ ✓, but 3(4) + 2(12) = 36 \neq 10$.

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.

🎯 Keep Practicing!

Master all sections for your best SAT score