bribrianna
Jan 5, 2012, 02:49 PM
This is Algebra II substitution... how do you solve it? And please no just the answer show your work please :(
1)2x+y=8 x-y=10 And I was also wondering if you mark it consistent,
independent or are there anything else your can
"label" the as?
2)3x+4y=23 -3x+y=2
ebaines
Jan 5, 2012, 03:06 PM
Starting with:
2x+y = 8
x-y = 10
From the second equation you can see that x = 10+y. So replace the 'x' in the first equation with '10+y', and you get:
2(10+y)+y = 8
Now you can simplify and solve for y. Then put that value for y back into the second equation and solve for x.
Alternatively, if you simply add these two equations together the 'y' terms cancel out:
(2x + y) +(x - y) = 8 + 10, or:
3x = 18
Now you can solve for 'x,' then put that value back into of the original two equations and solve for 'y'.
The second problem can be solve in a similar way. Post back with your answers and we'll check them for you.