9x=-21+2y \\\\ => \boxed{x=\frac{2y-21}{9}} \\\\ 2x+3y=16 \\\\ 2*\frac{2y-21}{9}+3y^{(9}=16^{(9} \\\\ 2(2y-21)+27y=144 \\\\ 4y-42+27y=144 \\\\ 31y=144+42 \\\\ 31y=186 \\\\ \boxed{y=\frac{186}{31}=6} \\\\ x=\frac{2*6-21}{9} \\\\ x=\frac{12-21}{9} \\\\ x=\frac{-9}{9} \\\\ \boxed{x=-1}"> 9 x − 2 y = − 21 <=> 9 x = − 21 + 2 y => x = 9 2 y − 21 2 x + 3 y = 16 2 ∗ 9 2 y − 21 + 3 y ( 9 = 1 6 ( 9 2 ( 2 y − 21 ) + 27 y = 144 4 y − 42 + 27 y = 144 31 y = 144 + 42 31 y = 186 y = 31 186 = 6 x = 9 2 ∗ 6 − 21 x = 9 12 − 21 x = 9 − 9 x = − 1
To solve the system of equations, start by rewriting one equation in terms of one variable. Substitute that expression into the other equation to find the values for both variables, resulting in x = − 1 and y = 6 . The solution is therefore the point ( − 1 , 6 ) .
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