Solve the system by elimination: $x+y=7$ and $3x+2y=10$.
A$x=4,\ y=3$
B$x=-4,\ y=11$
C$x=11,\ y=-4$
D$x=2,\ y=5$
Answer & Solution
Correct answer: B. $x=-4,\ y=11$
Multiply the first equation by 2 to get $2x+2y=14$. Subtract this from $3x+2y=10$ to obtain $x=-4$. Substituting into $x+y=7$ gives $-4+y=7$, so $y=11$.
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