Lets begin with our y=mx+b, our constant(b) is 800 that she earns as a salary, our x represents the amount she sells, m then represents the commission which is 8.25% so converting that to a decimal and replacing it as m gets us y = 0.0825x+800. Replace $4500 for x and we have y=0.0825(4500)+800 solve and we get $1171.25
To determine if a line is perpendicular to another, you must first determine the slope...
m = y1-y2/x1-x2
m of FK = 3-5/3-6 = -2/-3 = 2/3
m of FJ = 3-2/3-8 = 1/-5
m of FL = 3-0/3-5 = 3/-2
m of KJ = 5-2/6-8 = 3/-2
m of KL = 5-0/6-5 = 5
m of JL = 2-0/ 8-5 = 2/3
In order for two lines to be perpendicular, their slopes must be opposite reciprocals...
FK is perpendicular to FL
FK is perpendicular to KJ
JL is perpendicular to FL
JL is perpendicular to KJ
FJ is perpendicular to KL
X+y=57
y=x+15
x+x+15=57
2x=42
x=21
y=21+15
y=36
