SOLUTION: Hey there, I have recently been set a simultaneous equations hwk that up till now I have found rather easy! My problem occurs at a new type of question I have not been taught about

Question 1015473: Hey there, I have recently been set a simultaneous equations hwk that up till now I have found rather easy! My problem occurs at a new type of question I have not been taught about. I will provide 2 questions for reference: and is the first pair. The 2nd is and is the other pair. I believe that I need to +/-the single integer with no algebraic term, to make it not equal 0, and the rearrange and substitute in. However, when I do this, say with the 2nd, I get , which I know isn't right, as a friend showed me the answer. But I want to understand how I get there! As the answer is . Thanks for reading and helping me out!
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
2x - y + 1 = 0
3x + 2y + 4 = 0
-------
4x - 2y + 2 = 0 1st eqn times 2
3x + 2y + 4 = 0
--------------------- Add
7x + 6 = 0
x = -6/7
y = 2x + 1 (1st eqn)
y = -5/7
=====================
3x - y + 5 = 0
5x + y - 13 =0
----------------------- Add
8x - 8 = 0
x = 1
=====================================
---
y = 8
================

RELATED QUESTIONS
Hey there, I have been given a simultaneous equations hwk, and have been doing fine up... (answered by ikleyn)

Dear sir/ma'am, I have a question regarding how to solve Quad. Equations. My brother... (answered by edjones)

Simultaneous Solution of Systems of Linear Equations 3/5x + 3/8y + 800 = x 6/10 +... (answered by checkley71)

Hi, I have been assigneda rather large piece of homework that is mostly easy, however it... (answered by stanbon)

Quadratic equations are not my strong suit and I recently failed a quiz based on them. My (answered by richard1234)

I have gone on-line and found some free calculators for graphing and have been able to... (answered by stanbon)

X+3 X _________ - _____ = X 4 2 I have worked this problem for... (answered by Mathtut)

hey i have a question on my homework (answered by MathLover1)

We are finding the equations for parabola's and graphing them. Here is one of my... (answered by Alan3354)