Actually, she worked for seven hours, so I'll solve for that.
7.20 x 3 = 21.6
6.75 x 4 = 27
21.6 + 27 = 48.6
48.6 /2 = 24.3
Her average should be $24.3 If she did work six hours, just multiply 6.75 x 3 and do what I did.
8y-4x=2x+12y
x+2y+8y-4x=180
10y-3x=180
x+2y+2x+12y=180
14y+3x=180
24y=360
y=15
8(15)-4x=2x+12(15)
120-4x=2x+180
120=6x+180
-60=6x
x=-10
(C) jasmyne is the one with the proportinal relationship
Plug in your Y value into the bottom equation like so:
4x + 3x-3=11, combine like terms
7x-3=11 solve for x
7x= 14
x=2
Plug in x value into first equation
y = 3(2) -3
y= 6-3, y = 3
answer: (2,3)