SOLUTION: I am working on a test review sheet from my professor and having trouble with one of the problems. We are studying inequalities in 2 variables and graphing. Here is the problem..

Algebra ->  Graphs -> SOLUTION: I am working on a test review sheet from my professor and having trouble with one of the problems. We are studying inequalities in 2 variables and graphing. Here is the problem..      Log On


   

Question 70979: I am working on a test review sheet from my professor and having trouble with one of the problems. We are studying inequalities in 2 variables and graphing. Here is the problem...Graph 7x > 3y. I have tried dividing both sides by 3 and adding -3y to both sides, but I must be in the middle of a brain fog and can not figure it out. Any help would be GREATLY appreciated.
Thanks,
Yvonne
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
You dont need to divide both sides by 3, you just need to get everything to one side
7x+%3E+3yStart with given inequality
7x-3y%3E0Subtract 3y from both sides
To graph the inequality, we must graph the equations first.
7x=3yChange the inequality to an equation and solve for y
y=%287%2F3%29xNow we can graph the equation
This equation is the boundary of our shaded region
graph%28+300%2C+200%2C+-5%2C+5%2C+-5%2C+5%2C+7x%2F3+%29
Now let x and y be any 2 numbers such as x=1 and y=1 and plug them into our inequality
7%281%29-3%281%29%3E0
4%3E0Since this is true we can shade the entire region around this point,
which in this case, its anything below the line y=7/3x.


Note: Winplot (http://math.exeter.edu/rparris/winplot.html) allows you to graph inequalities and shade the correct regions.