Question

3x+4y=11 2x+y=-1

Answer 1

3x+11+4y then divide 4 by all the numbers then its: y= 2 3/4 + 3/4x

Answer 2

\[
3 x + 4 y = 11 \\
2 x + y = -1\\
\text {Multiply the second equation by -4 and add }\\
3 x + 4 y = 11 \\
-8 x -4 y = 4\\
-5 x =15\\
x= -3

\]
Replace x by its value in the first equation to get
\[
-9 +4y =11\\
4 y = 20\\
y=5
\]

Answer 3

check it with Wolframalpha
http://www.wolframalpha.com/input/?i=solve+3+x+%2B+4+y+%3D+11+and++2+x+%2B+y+%3D-1