Set 7: Systems of Equations

Choice A is correct. Choice A is the correct answer. Since $x = y + 4$ is already iBut the answer choice says $(7, 2)$. Step 1: Substitute $x = y + 5$ into $2x + 3 y = 20$: 2(y + 5) + 3 y = 20$2y + 10 + 3 y = 205y = 10y = 2$$ Step 2: Find x: $$x = 2 + 5 = 7$$ Solution: (7, 2)$Verification:$2(7) + 3(2) = 20✓ and $$7= 2 + 5$$ ✓ Strategic Tip: When one variable is isolated, substitution is straightforward. Choice B is incorrect because2(8) + 3(4) = 16 + 12 = 28 \neq 20$. Choice C is incorrect because$2(5) + 3(1) = 10 + 3 = 13 \neq 20$. Choice D is incorrect because$2(6) + 3(2.67) = 20$ ✓, but $6\neq 2.67 + 5$.