CHECK ATTACHMENT PLEASE

Question

anonymous · Answer

attachment

mathstudent55 · Answer

Let's write our 2 original equations.

$x + 3y = 5$   Eq. 1

$7x - 8y = 6$   Eq. 2

mathstudent55 · Answer

The problem is asking for a new system of equations which is obtained by keeping equation 2 unchanged, and equation 1 is replaced by the sum of equation 1 and a multiple of equation 2.

The new system of equations will be:

$x + 3y = 5$   Eq. 1 kept unchanged

$\_\_\_\_\_\_\_\_\_\_$   A new equation replacing Eq. 2

mathstudent55 · Answer

Now we need to read in the problem what the new equation that replaces equation 2 is.

"If equation 2 is multiplied by 1, ..."

We are told that equation 2 is multiplied by 1.
We already were told that we needed to add a multiple of equation 2 to equation 1.
Now we know that the multiple of equation 2 is obtained by multiplying equation 2 by 1.

What is equation 2 (below) multiplied by 1 on both sides?

$7x - 8y = 6$   Eq. 2

anonymous · Answer

can you try it out? :)
we can't do it for u

mathstudent55 · Answer

@dom4958 Are you there?

anonymous · Answer

@mathstudent55 yes

anonymous · Answer

@dom4958 then try it out

anonymous · Answer

well if I'm multiplying equation 2 by 1 it would still be the same wouldn't it? or would the - sign change next to  8y?

mathstudent55 · Answer

Ok. What is any number multiplied by 1?
What is 2 * 1 =
3 * 1 = 
pi * 1 = 
What does multiplying by 1 do to a number?

anonymous · Answer

@mathstudent55 nothing. it stays the same

mathstudent55 · Answer

Exactly. Multiplying by 1 does not change a number, so multiplying a whole equation by 1 does not change the equation.

mathstudent55 · Answer

That means when we multiply the second equation by 1, we end up with the second equation, just as it was originally.

mathstudent55 · Answer

$7x - 8y = 6$   Eq. 2 multiplied by 1

mathstudent55 · Answer

Now we add Eq. 1 to Eq. 2 multiplied by 1:

$~~~~~~~~x + 3y = 5$   Eq. 1
$+~~~7x - 8y = 6$   Eq. 2 multiplied by 1
$\_\_\_\_\_\_\_\_\_\_\_\_\_\_$

mathstudent55 · Answer

Do you know how to add the equations in the response above?

mathstudent55 · Answer

Add like terms that are placed one above the other.
What is x + 7x = ?

anonymous · Answer

i think he's afk just waiting for the answer

anonymous · Answer

sorry I'm back, give me a moment to read what you just said

anonymous · Answer

would this be correct or am i off track?
      x+3y=5   
+   7x−8y=6   
______________
8x - 5y =11???

mathstudent55 · Answer

Correct.

mathstudent55 · Answer

Now you replace equation 1 by this new equation, and equation 2 remains the same as it was.
What is the new system of equations?

anonymous · Answer

8x - 5y =11 Eq.1
 7x−8y=6  Eq.2

mathstudent55 · Answer

Original system                                               New system
$x+3y=5$      Eq. 1     ---replaced by--->   $8x - 5y = 11$
$7x−8y=6$    Eq. 2     ---remains as---->   $7x - 8y = 6$

mathstudent55 · Answer

Exactly.
Now read the choices and choose the correct one.

anonymous · Answer

B thank you so much. you made it really clear i appreciate it

mathstudent55 · Answer

Great. You're welcome.
Notice that you did all the work. I just guided you through it.
When you have a problem like this one, break down the instructions into small steps and do one step at a time until you get it all done.
Good job!

anonymous · Answer

@mathstudent55 thanks, i honestly have no idea how people can memorize this. I'm good at every other subject but math just gets me lol

mathstudent55 · Answer

Each of us has our strong and weak subjects. This way we can help each other.