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9x-2y=-21 2x+3y=16 Substitution

User Piotr
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9x-2y=-21 \\\\ <=> 9x=-21+2y \\\\ => \boxed{x=(2y-21)/(9)} \\\\ 2x+3y=16 \\\\ 2*(2y-21)/(9)+3y^((9)=16^((9) \\\\ 2(2y-21)+27y=144 \\\\ 4y-42+27y=144 \\\\ 31y=144+42 \\\\ 31y=186 \\\\ \boxed{y=(186)/(31)=6} \\\\ x=(2*6-21)/(9) \\\\ x=(12-21)/(9) \\\\ x=(-9)/(9) \\\\ \boxed{x=-1}
User ShiyamTJ
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