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Im not good at math pls anyone???

Im not good at math pls anyone???-example-1

2 Answers

1 vote


</em></strong><strong><em>2x - y = 9 </em></strong><strong><em>\</em></strong><strong><em>:</em></strong><strong><em> x + 3y = -6 \\ x = -3y - 6 \\ 2•(-3y-6) - y = 9 \\- 7y = 21 \\ 7y = - 21&nbsp; \\ y = - 3&nbsp; \\ x = -3y-6 \\ y = -3 \\ x = -3(-3)-6 = 3&nbsp; \\ answer \: is \: &nbsp;{x,y} = {3,-3}


</em></strong><strong><em>2x + y = -7 &nbsp; \: \: \: \: \: 6x - 3y = 14 \\ y = -2x - 7 \\ 6x - 3•(-2x-7) = 14 \\ 12x = -7 \\ 12x = - 7&nbsp; \\ x = - 7/12&nbsp; \\ x = -7/12 \\ y = -2x-7 \\ y = -2(-7/12)-7 = -35/6&nbsp; \\ so \: the \: answer \: is \: &nbsp;{x,y} = {-7/12,-35/6}

User Artur Vakhrameev
by
6.1k points
8 votes

Answer:

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.

User Holyxiaoxin
by
6.4k points