Solving systems of equations
2x=5y
x+y=1
2007-09-24 11:02:24 · 3 answers · asked by Mamasboy 4 in Education & Reference ➔ Homework Help
please show work
2007-09-24 11:05:55 · update #1
I'm going to do this a very uncommon way. Follow along carefully.
Okay, so you have your two equations. Multiply the second equation by 2, and move 5y on the first equation to the other side. You have:
2x - 5y = 0
2x + 2y = 2
Now, subtract the two *equations*.
-7y = -2
Divide both sides by -7.
y = 2/7
Plug that in to one of the equations.
x + 2/7 = 1
Get x alone.
x = 5/7
So, your answers are:
x = 5/7
y = 2/7
You can check these if you would like.
2007-09-24 11:07:26 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Simultaneous equations in 2 unknowns:
2x=5y
x+y=1
Eliminate 1 unknown by substitution:
x = 1 - y
2(1 - y) = 5y
Solve for y:
2 - 2y = 5y
2 = 7y
y = 2/7
Substitute to find x:
x = 1 - 2/7 = 5/7
Proof:
2(5/7) = 5(2/7)
10/7 = 10/7
Both sides equal.
2007-09-24 18:12:17 · answer #2 · answered by Robert S 7 · 0⤊ 0⤋
y = 2/7
x = 5/7
2007-09-24 18:07:19 · answer #3 · answered by Anonymous · 0⤊ 0⤋