im not good at math pls anyone???

Answer:
Step-by-step explanation
#1)
Step 1:
Set any equation to one variable. Let's pick the first equation.
I would make 2x-y=9 into y=2x-9.
Step 2:
Then I would subsitute 2x-9 into the (y) for the 2nd equation. The equation should look like x+3(2x-9)=-6
Step 3:
I then distribute the 3 to the 2x+9 in which the expanded form would look like x+6x-27=6
Step 4:
Then I would combine the X terms and move the -27 to the other side.
7x=33
Step 5:
I then would solve for X which is x=33/7.
Step 6:
We would plug in 33/7 for X and any of the equation whether it is the top or bottom and you should recieve your answer for Y.
#2)
Step 1:
Like #1 I would do the same, but this time let's do it for X.
I would make 2x-y=7 into x=(y+7)/2
Step 2:
I then would subsitute [(y+7)/2] into (x) for the 2nd equation below.
It should be 6[(y+7)/2]-3y=14.
Step 3:
I would then do distributive property and expand the equation.
3y+21-3y=14
Step 4:
I would then combine the Y and move the 21 over to the right side.
0y=-7
Step 5:
This shows that 0 cannot equal to 7 therefore this equation is unsolvable or we refer to as undefined.
[tex]2x - y = 9 \: x + 3y = -6 \\ x = -3y - 6 \\ 2•(-3y-6) - y = 9 \\- 7y = 21 \\ 7y = - 21 \\ y = - 3 \\ x = -3y-6 \\ y = -3 \\ x = -3(-3)-6 = 3 \\ answer \: is \: {x,y} = {3,-3} [/tex]
[tex]2x + y = -7 \: \: \: \: \: 6x - 3y = 14 \\ y = -2x - 7 \\ 6x - 3•(-2x-7) = 14 \\ 12x = -7 \\ 12x = - 7 \\ x = - 7/12 \\ x = -7/12 \\ y = -2x-7 \\ y = -2(-7/12)-7 = -35/6 \\ so \: the \: answer \: is \: {x,y} = {-7/12,-35/6} [/tex]