Question

3x-y=3
9x - 3y=9
solve this by substitution method only...
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Answer 1

Answer:

hey frnd

here is your answer -

Step-by-step explanation:

3x-y=3

9x-3y=9

by substitution..

9(3x-y=3) = 27x - 9y=27

3(9x-3y)=9 = 27x -9y = 27

27x - 9y = 27

27x - 9y = 27

(-) (+) (-)

= 0

Answer 2

Answer:

Infinitely many solution

Step-by-step explanation:

Given :

To Find the values of x & y if,

3x - y = 3,

9x - 3y = 9,.

Solution :

We know that,

We need atleast 2 equations to find true values of 2 variables.

The given equation is only one

3x - y = 3,

The equation 9x - 3y = 9 is the same as 3x - y = 3

9x - 3y = 9 ⇔ 3(3x - y) = 3(3) ⇔ 3x - y = 3,.

For these equations to be consistent, There are infinitely many solutions as,

⇒ ( x , y ) = ( 0 , 3 ) ,( 1 , 0 ) ,.....∞

We substitute value of a variable (Which we got from one of the equations) on another equation is same as substituting the variable on the same equation,.

We will end up by cancelling both the variables and constants and end up with 0 = 0 (LHS = RHS)

By substitution,

⇒ 3x - y = 3

⇒ y = 3x - 3 ...(i)

By substituting value of y in that Equation,

⇒ 9x - 3y = 9

⇒ 9x - 3(3x - 3) - 9 = 0

⇒ 9x - 9x + 9 - 9 = 0

⇒ 0 = 0,. (As mentioned above)