Posted by **Jim** on Friday, November 9, 2012 at 1:35pm.

I need help solving this set of equations by substitution.

xy=2

3x − y + 5 = 0

I originally used (3x+5=y) and came up with (x=.333 and x=-2) but when I substitute it into the original equation I get (y=2 and y=1) and it is wrong according to my homework. Please help me!

- Algebra -
**Reiny**, Friday, November 9, 2012 at 3:27pm
ok, go with y = 3x+5

into the 1st

x(3x+5) = 2

3x^2 + 5x - 2 = 0

((3x-1)(x+2) = 0

x = 1/3 or x = -2 --- > you are correct

if x = 1/3, y= 3(1/3) + 5 = 6

if x = -2 , y = 3(-2) + 5 = -1

so x=1/3, y=6 OR x=-2, y =-1

I don't know how you got your values ???

## Answer This Question

## Related Questions

- Algebra SOLVING LINEAR EQUATIONS AND INEQUALITIES - Please help Im am Grade 5 ...
- Algebra - Solving Linear Equations and Inequalities Solve by eliminating x (this...
- Algebra I DONT KNOW HOW TO DO 3 VARIABLES - Solving Linear Equations and ...
- Algebra - I am helping my daughter with her algebra and we came across a symbol ...
- Algebra - A chemist mixed a 70% alcohol solution with a 30% alcohol solution to ...
- algebra - 5x-2y=-5 y-5x=3 substitution Substitute 5x +3 for y in the first ...
- Algebra - Solve: 3x-2y=10 2x+3y=-2 Graph: Substitution: Elimination: Show Your ...
- Algebra - solving linear equations w/ substitution - The question in the book ...
- Business Algebra - Produce an example of a system of equations to your fellow ...
- Pre-Calculus - If you solve the following system of equations by substitution, ...

More Related Questions