Question

Plzz solve this by substitution method.​

Answer 1

☞ Question :

➝ Solve the linear equation and find the value of x and y :-

$\mathtt{\dfrac{7 - 4x}{3} = y}$

$\mathtt{2x + 3y + 1 = 0}$

☞ To Find :

➝ The value of x and y .

☞ Method Used :

➝ By Substitution method .

☞ Concept :

➝ To solve this equation we have to first find the the value of one variable .

➜ Equation...(i)

$\mathtt{\dfrac{7 - 4x}{3} = y(Equation(ii)}$

➜ Equation...(ii)

$\mathtt{2x + 3y + 1 = 0}$

By solving it , we get :

$\mathtt{\Rightarrow 2x + 3y = -1(Equation</p><p>..(ii)}$

☞ Solution :

Equation..(i)

$\mathtt{\dfrac{7 - 4x}{3} = y}$

Equation..(ii)

$\mathtt{\Rightarrow 2x + 3y = -1}$

Putting the value, of y in the equation ,we get :

$\mathtt{\Rightarrow 2x + 3 \times \dfrac{7 - 4x}{3} = -1}$

$\mathtt{\Rightarrow 2x + \cancel{3} \times \dfrac{7 - 4x}{\cancel{3}} = -1}$

$\mathtt{\Rightarrow 2x + 7 - 4x = -1}$

$\mathtt{\Rightarrow 7 - 2x = -1}$

$\mathtt{\Rightarrow - 2x = -1 - 7}$

$\mathtt{\Rightarrow -2x = -8}$

$\mathtt{\Rightarrow \cancel{-2}x = \cancel{-8}}$

$\mathtt{\Rightarrow x = 4}$

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

$\mathtt{2x + 3y = -1}$

$\mathtt{\Rightarrow 2(4) + 3y = -1}$

$\mathtt{\Rightarrow 8 + 3y = -1}$

$\mathtt{\Rightarrow 3y = -1 - 8}$

$\mathtt{\Rightarrow 3y = -9}$

$\mathtt{\Rightarrow \cancel{3}y = \cancel{-9}}$

$\mathtt{\Rightarrow y = -3}$

Hence , the value of x is 4 and y is - 3.

☞ Verification :

Putting the value in the equation :

$\mathtt{2x + 3y + 1 = 0}$

We Get,

$\mathtt{\Rightarrow 2 \times 4 + 3 \times -3 + 1 = 0}$

$\mathtt{\Rightarrow 8 - 9 + 1 = 0}$

$\mathtt{\Rightarrow 9 - 9 = 0}$

$\mathtt{\Rightarrow 0 = 0}$

Hence , LHS = RHS.

Answer 2

refer to the attachment