Set 9: Systems of Equations (Advanced)

Choice A is correct. Choice A is the correct answer. Let $a$ = pounds of apples and $o$ = pounds of oranges. System: $\begin{cases} a + o = 12 \\ 1.5 a + 2 o = 21 \end{cases}$ Step 1: From first: $o = 12 - a$ Step 2: Substitute: $$$1.5a + 2(12 - a) = 211.5a + 24 - 2 a = 21$-0.5 a = -3a = 6 Solution: 6 pounds of apples Verification: $6+ 6 = 12$ ✓ and $1.5(6) + 2(6) = 9 + 12 = 21$ ✓ Strategic Tip: Decimal coefficients can be eliminated by multiplying, but substitution works fine too. Other choices fail verification.