Question 147586
1. Substitution Method:  
{{{7x + 3y = -9}}}{{{-6y + y =22}}}. 


-First combine like terms on the right side.  You end up with {{{-5y=22}}}. Then divide by -5 on both sides and get {{{y=-22/5}}}.  Then since you have y, plug it in to the first equation and get {{{7x-3(-22/5)=-9}}}.  Then multiply -3 by -22/5.  And get {{{66/5}}}.  Then it looks like this {{{7x-66/5=-9}}}.  Then add 66/5 to both sides and get {{{7x=21}}}.  Then divide both sides by seven and get {{{x=3}}}.  So y=-22/5 and x=3.


 
2. Solve and Graph
2x -14 _< -7 or x -4 _> 1
Solution is {x/x _<  ? or x  _>  ?}


{{{2x -14<= -7}}} divide both sides by 2 and get {{{x-7<=-7/2}}}. Then subtract seven and get {{{x<=7/2}}}. {{{x -4 >= 1}}} add four to both sides {{{x>=5}}}. Graph them both as x=7/2 and x=5 first.

*[invoke describe_linear_equation 1, 0, 7/2]
*[invoke describe_linear_equation 1, 0, 5]

Then since it is {{{x<=7/2}}}, shade every part of that graph to the left of x=7/2.  Then since it is {{{x>=5}}}, shade every part of that graph to the right of x=5.  Then you are done solving and graphing.

If you still need help graphing inequalities, check out my lesson:
http://www.algebra.com/algebra/homework/Graphs/Inequalities-Made-Easy.lesson