Question

If 4x + 5 = – 7 , then find the value of 2x + 9

Answer 1

• As per the data given in the question, we have to find the value of the expression.

        Given data:- $4x+5=-7.$  

        To find:- The value of the expression $2x+9.$

        Solution:-

• Here, we will use the below following steps to find a solution using the transposition method:

• Step 1:- we will Identify the variables and constants in the given simple equation.

• Step2 -then we Simplify the equation in $LHS$  and $RHS$.

• Step 3:- Transpose or shift the term on the other side to solve the equation further simplest.

• Step 4:- Simplify the equation using arithmetic operation as required that is mentioned in rule 1 or rule 2 of linear equations.

• Step 5:- Then the result will be the solution for the given linear equation. By using the transposition method. we get,

              $4x+5=-7\\4x=-7-5\\4x=-12\\x=\frac{-12}{4} \x=-3.$

    Hence we get $x=-3.$

    Now put $x=-3$ in the equation  $2x+9.$

     So that,

            $2x+9\\=2(-3)+9\\=-6+9\\=3.$

   Hence we will get the value will be 3.

Answer 2

To find : value   $2x + 9$

Given equation : $4x + 5 = -7$

• According to equation to find the value of $2x + 9$  first  of all we will find value of $x$ form given equation : $4x + 5 = -7$  
• To solve we will arrange terms with variables at LHS and constants at RHS .

                       $4x = -7 - 5$

• Now , by simply performing addition and on further solving division we get the value of $x$ .

    ⇒                  $4x = - 12$

    ⇒                    $x = - 3$    

Now , to find value of  $2x + 9$

Substituting value of $x$ in $2x + 9$

              $2x + 9$ $= 2 ( -3 ) + 9$

                        $= -6 + 9$

                        $= 3$

Hence , value of  $2x + 9$ is $3$.