Question

Solve 3x-y=3and 9x-6y=12 linear equations by substitution method

Answer 1

Answer:

$x=\frac{2}{3}$ , $y=-1$

Step-by-step explanation:

In substitution method, you should first solve for one variable (like $x$ or $y$).

And after that, Substitute that expression into the other equation.

Let's solve for $y$ in the first equation. ($3x-y=3$)

1. $3x-y=3$, add both sides $+y$.
2. $3x=y+3$, subtract both sides $-3$.
3. $3x-3=y$.
4. It will be $y=3x-3$.

Now we are going to substitute this expression into the second equation.

1. $9x-6y=12$, Here we replace $3x-3$ instead of $y$.
2. $9x-6(3x-3)=12$, Now we simplify this.
3. $-9x+18=12$.
4. From here we find $x$. $x = \frac{2}{3}$.

And now we substitute $x$ into the first equation and solve for $y$.

1. $3x-y=3$, Here we replace $\frac{2}{3}$ instead of $x$.
2. $3(\frac{2}{3})-y=3$, Now we simplify this.
3. $2-y=3$.
4. From here we find $y$. $y=-1$