Answer: $15.94
Step-by-step explanation:
Let r be your rate you get paid per hour normally. Let's set up this equation.
(30 * r) + 4(1.5 * r) = 573.83
30r + 6r = 573.83
36r = 573.83
r = 15.94 (rounded)
You get paid $15.94 hourly.
 
        
             
        
        
        
Sina - (cosa)(tanb)/cosa + (sina)(tanb)
sina ≡ (tana)(cosa)
(tana)(cosa) - (cosa)(tanb)/cosa + (tana)(cosa)(tanb)
= cosa(tana - tanb)/cosa(1 + tanatanb)
(cosas cancel out)
= (tana - tanb)/(1 + tanatanb) ≡ tan(a-b)
        
             
        
        
        
Use this systems of equations to solve:
x = first antifreeze
y = second antifreeze

Isolate y.
x + y = 15
Subtract x from both sides.
y = -x + 15
Substitute y into the other equation.
.2x + .12(-x + 15) = .18(15)
Simplify.
.2x - .12x + 1.8 = 2.7
Subtract 1.8 from both sides.
.08x = .9
Divide both sides by .08
x = 11.25
Substitute x in the equation that we isolated y in.
y = -11.25 + 15
y = 3.75
11.25 L of the first antifreeze and 3.75 L of the second.