A system of equations is given below:

y = 4x − 3
2x + 7y = 41

Which of the following steps could be used to solve by substitution?

2(y = 4x − 3) + 7y = 41
4x − 3 = 2x + 7y
2x + 7(4x − 3) = 41
2(y = 4x − 3)

Question

A system of equations is given below: 

y = 4x − 3 
2x + 7y = 41 

Which of the following steps could be used to solve by substitution?

 2(y = 4x − 3) + 7y = 41
 4x − 3 = 2x + 7y
 2x + 7(4x − 3) = 41
 2(y = 4x − 3)

k_lynn · Answer

If the first equation says y=4x-3 then you would be able to put in 4x-3 for every y you see in this equation (2x+7y=41), right?

anonymous · Answer

so 4x-3=2x+7y

k_lynn · Answer

No, not quite.  $$4x-3\neq2x+7y$$But$$y =4x-3$$

k_lynn · Answer

All you have to do is put in 4x-3 in for every y you see in this equation (2x+7y=41) Because $$y=4x-3$$

anonymous · Answer

so  2x + 7(4x − 3) = 41

k_lynn · Answer

Yep, you got it.  $$2x+7(4x-3)=41$$

anonymous · Answer

Thank you i was really confused

k_lynn · Answer

Sure, no problem. I made a tutorial yesterday about Solving systems of equations using substitution. If you want to, you can take a look at it. http://openstudy.com/study#/updates/551aa38ae4b05a89ab81ab30

anonymous · Answer

Thank you

k_lynn · Answer

You're welcome.