Question

Please, please, please help! I need help with 2 questions. I'll fan/medal.

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A system of equations is given below:

y = 3x + 4
2x + 3y = 10

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

3x + 4 = 2x + 3y
2x + 3(3x + 4) = 10
2(3x + 4) + 3y = 10
3(y = 3x + 4)

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A set of equations is given below:

Equation S: y = x + 9
Equation T: y = 2x + 1

Which of the following steps can be used to find the solution to the set of equations?

x = 2x + 1
x + 9 = 2x
x + 1 = 2x + 9
x + 9 = 2x + 1

Answer 1

1)
When using susbstion its best to use it if it tells you that a varible equals something
y = 3x + 4
2x + 3y = 10
In this case it is a given that y equals something so we use that information and plug it into the 2nd equation like this
\(\huge\rm\color{black}{2x + 3(3x+4)=10}\)

Answer 2

It erased my work here is what i had typed
http://prntscr.com/7qa7fu

Answer 3

That should take care of #1

Answer 4

Try #2 by yourself let me know what you get

Answer 5

@Moe95 Okay so since #2 tells us what y equals on both equations, shouldn't I combine the two equations? Or do I try for x?

Answer 6

@Moe95 And thank you btw

Answer 7

You are welcome and yes! Thats exactly what you do! So the answer is......*drum rolls* ...

Answer 8

@Moe95 The answer for #2 is D ? :D

Answer 9

yes! :D Good job! :)

Answer 10

@Moe95 Thank you so much for helping me!

Answer 11

No problem! :)