Question

When graphing the inequalities 9x+8y<72 and -7x-4y<=28 what would be the solution set? Also what would be thier intersection?

Answer 1

9x+8y<72
8y < -9x + 72
y < (-9/8)x + 9
sketch the line y = (-9/8)x + 9 and draw a dotted line.
Shade in the region below the line

-7x - 4y ≤ 28
-4y ≤ 7x + 28
y ≥ (-7/4)x - 7
draw a solid line for y = (-7/4)x - 7
and shade in the region above that line

your solution is the part shaded by both.

to find their intersection, solve them as equations.