Question

d) Solve for x: 21 - 3(x-7)= x + 20.​

Answer 1

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

      Given data:- $21-3(x-7)=x+20.$

      To find:- value of the expression.

      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.
• Step 2:-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,

          $\Rightarrow 21-3(x-7)=x+20\\\Rightarrow 21-3x-21=x+20\\\Rightarrow -3x-x=20-21-21\\\Rightarrow -4x=-22\\\Rightarrow x=\frac{11}{2}.$

   Hence, the value will be $\frac{11}{2}.$

     

Answer 2

Answer:

Step-by-step explanation:

Given : The expression is $21-3(x-7)=x+20$

To find : The value of $x$.

Solution :

• The given expression is, $21-3(x-7)=x+20$  
• We have to find the value of $x$.
• In order to find the value of $x$, we have to solve the given expression using BODMAS rule.
• It states that, while solving any algebraic expression, we should first solve the B-Brackets, O-Order, D-Division, M-Multiplication, A-Addition and S-Subtraction.

• By using the above rule, on solving given expression, we get

      $21-3(x-7)=x+20$

• Multiply $-3$ with $(x-7)$, we get

           ∴ $21-3x+21=x+20$

                  ∴ $42-3x=x+20$

• Transpose terms with with variables on one side and constant terms on other side, we get

                        ∴ $42-20=x+3x$

                            ∴ $22=4x$

                            ∴ $x=\frac{22}{4}$

                            ∴ $x=\frac{11}{2}$

• ∴ The value of $x$ is $\frac{11}{2}$.