# Thread: system of equations using substitution method

1. ## system of equations using substitution method

How would I solve this problem using the substitution method. Any help woud be greatly appreciated. :~}

x=y+3
4x+y=2

2. ## Im not sure if i did it right

4(y+3)+y=2

4y+12+y=2
x=y+3
5y+12=2 (-12 from both sides)
5y=-10 (/ both sides by 5)
y=-2

Then I found x
x=-2+3
x=1

3. ## Assistance

2 Unknowns by Substitution Calculator

Enter 4x+y=2 for Equation 1 and x-y=3 for Equation 2 and Press Calculate.

Solution: (x, y) = (1, -2)

if you want to see the opposite way of substitution method, switch equation 1 and equation 2 in the entry boxes. :-)

Sometime later this week, I'll clean up the math portion to not show denominators of 1 and coefficients of 1. It looks like you missed a sign. Look at the section where it says:

"Now, group like terms by getting the y variables on one side of the equation and the constants on the other side:"

I hope this helps, let me know if you have questions.

4. How would i enter this into my calculator? I see an x button but no y button

5. Originally Posted by mathceleb
2 Unknowns by Substitution Calculator

Enter x-y=3 for Equation 1 and 4x+y=2 and Press Calculate.

(x, y) = (1, -2)

if you want to see the opposite way of substitution method, switch equation 1 and equation 2 in the entry boxes. :-)
I dont think it is appropriate to suggest this sort of method for what is a very easy problem.

4(y+3)+y=2

4y+12+y=2
x=y+3
5y+12=2 (-12 from both sides)
5y=-10 (/ both sides by 5)
y=-2

Then I found x
x=-2+3
x=1
Keep up the good work. ( and possibly change your username )

6. I wish i could change my user name but i am not that good at math i do all right on the home work and stuff but when the tests come around i forget how to solve each individual problem i use one type of method on the wronge type of problem and get totaly confused lol

7. Originally Posted by bobak
I dont think it is appropriate to suggest this sort of method for what is a very easy problem.
I thought it would help to show him where he missed his sign. I thought sites where you did not sell anything were acceptable. If they are not, let me know and I won't post anymore.

8. Originally Posted by mathceleb
I thought it would help to show him where he missed his sign. I thought sites where you did not sell anything were acceptable. If they are not, let me know and I won't post anymore.
There is nothing wrong with your posting a site contains a program that will give students their answers. However the main aim of this site is to teach how to do the problems, not simply show them, and a suggestion like this will likely bend a few noses.

-Dan