Question

if point (-3,a+4)lies on the graph of the equation 3x=y+7a then find value of a also find a solution of the equation​

Answer 1

Answer:

a = - 13/8   and   solution is ( -3, 19/8 ).

Step-by-step explanation:

As ( - 3 , a + 4 ) lies on 3x = y + 7a, it must satisfy ( - 3 , a + 4 ) = ( x , y ).

 When, ( x , y ) = ( - 3, a + 4 )

⇒ 3( - 3 ) = ( a + 4 ) + 7a

⇒ - 9 = a + 4 + 7a

⇒ - 9 = 8a + 4

⇒ - 9 - 4 = 8a

⇒ - 13 = 8a

⇒ - 13/8 = a

   Hence, y = a + 4

                = -13/8 + 4

                = (-13+32)/8

                = 19/8

Hence,  a solution of this eq. is ( -3, 19/8 ).

Answer 2

$\sf{\underline{Answer\::}}$

Value of a = $\sf{\dfrac{-13}{8}}$

$\sf{Solution\: of \:equation\: =\:(x,y)\:=(-3,\dfrac{19}{8})}$

$\sf{\underline{Explanation\::}}$

Given points (-3, a+4) lies on the graph of the equation : 3x = y+7a.

Which means that the given coordinate points satisfies the equation.

It is seen that the coordinate points are written as : (x,y)

If we compare the given coordinate points then, x = -3 and y = a +4.

We have to solve for the value of a.

Take the given equation and plug in the value of x and y in equation.

=> $\sf{3x=y+7a}$

=> $\sf{3(-3)=(a+4) + 7a}$

=> $\sf{-9=a+4+7a}$

=> $\sf{-9=8a+4}$

=> $\sf{-9-4=8a}$

=> $\sf{-13=8a}$

=> $\sf{\dfrac{-13}{8}=a}$

The value of a = $\sf{\dfrac{-13}{8}}$

Now,the solution of the equation will be the coordinate points, for x we have -3 and for y we have the value of a plus 4.

Solving for y :

=> $\sf{y=a+4}$

=> $\sf{y=\:\dfrac{-13}{8}\:+\:4}$

=> $\sf{y=\:\dfrac{-13+32}{8}}$

=> $\sf{y=\:\dfrac{19}{8}}$

Solution of the equation :

• $\sf{(x,y)\:=(-3,\dfrac{19}{8})}$