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Giving 40 points

Solve each system by substitution

Giving 40 points Solve each system by substitution-example-1
User Joakimbl
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1 Answer

7 votes

Explanation:


\underline{ \underline{ \text{Given}}} :

  • -4x - y = 19 -------- Equation ( i )
  • x - 2y = -7 ----------- Equation ( ii )


\underline{ \underline{ \text{To \: find}}} :

  • Value of x & y


\underline {\underline{ \text{ Solution}}} :

From equation ( i ) :

-4x - y = 19

-y = 19 + 4x

-y = - ( -19 - 4x )

y = -4x - 19 ------ Equation ( iii )

Substituting the value of y from equation ( iii ) in equation ( ii ) , we get :


\tt{x - 2y = - 7 }


\tt{x - 2( - 4x - 19) = - 7}


\tt{x + 8x + 38 = - 7}


\tt{9x = - 7 - 38}


\tt{9x = - 45}


\tt{x = ( - 45)/(9)}


\boxed{ \tt{x = - 5}}

Substituting the value of x in equation ( i ) , we get :


\tt{ - 5 - 2y = - 7}


\tt{ - 2y = - 7 + 5}


\tt{ - 2y = - 2}


\tt{y = ( - 2)/( - 2)}


\boxed{ \tt{y = 1}}

The possible solution of the system is ordered pair ( x , y ) = ( -5 , 1 ) .


\red{ \boxed{ \boxed { \tt{Our \: final \: answer : \boxed{ \tt{( - 5 \:, 1 \: )}}}}}}

Hope I helped ! ツ

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User Jpenninkhof
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