4

Set 5: Systems of Equations (Advanced)

Explanation

Answer: C

Two numbers have a sum of 24 and a difference of 8. What is the larger number?

A.

14

B.

18

C.

16

✓ Correct
D.

12

Detailed Explanation

Choice C is correct. Choice C is the correct answer. Let xx be the larger number and yy be the smaller number. System: {x+y=24xy=8\begin{cases} x + y = 24 \\ x - y = 8 \end{cases} Step 1: Add the equations to eliminate yy: 2x = 32$x = 16$$ Step 2: Find $y$ using $x + y = 24$: 16+ y = 24$y = 8Solution:Thelargernumberis16.Verification:Solution: The larger number is 16. Verification:16+ 8 = 24and✓ and16- 8 = 8StrategicTip:Sumanddifferenceproblemsareperfectforeliminationmethod.ChoiceAisincorrectbecause✓ Strategic Tip: Sum and difference problems are perfect for elimination method. Choice A is incorrect because14+ 10 = 24,but✓, but14- 10 = 4 \neq 8.ChoiceBisincorrectbecause. Choice B is incorrect because 18+ 6 = 24,but✓, but18- 6 = 12 \neq 8$$. Choice D is incorrect because this is the smaller number, not the larger one.

Key Steps:

The correct answer is 16

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