How do you graph the system of linear inequalities #5x-3y<=4# and #x+y<8# and #y>3#?

1 Answer
Jun 8, 2018

f1(x,y) = 5x - 3y - 4 <= 0
f2(x,y) = x + y - 8 < 0
f3(y) = y - 8 > 0
This system of linear inequalities in 2 variables must be solved by graphing.
First, graph the 2 lines f1(x,y) and f2(x,y) by axis intersects.
f1(x,y) = 5x - 3y - 4 = 0
x = 0 --> #y = - 4/3#
y = 0 --> #x = 4/5#
f2(x,y) = x + y - 8 = 0
x = 0 --> y = 8
y = 0 --> x = 8
The solution set of #f(1(x,y) <= 0# is the area below the line f1(x,y)
The solution of f2(x,y) < 0 is the area below the line f2(x,y)
The solution set of f3(x,y) > 3 is the area above the line y = 3.
The solution set of the system is the commonly shared area of the 3 above solutions sets.