Answer:
5 shirts must be sold.
Step-by-step explanation:
First, set up the equation. Each shirt (x) is sold for $16: 
For every amount (y) for x: (y)(x) = (16)(y) 
The cost is $4, with the setup fee as $60.
(16)(y) = (4)(y) + 60
16y = 4y + 60
Isolate the variable (y). Note the equal sign, what you do to one side, you do to the other. First, subtract 4y from both sides.
16y (-4y) = 4y (-4y) + 60
16y - 4y = 60
12y = 60
Next, isolate the variable (y). Divide 12 from both sides.
(12y)/12 = (60)/12
y = 60/12
y = 5
5 shirts must be sold. 
To check, plug in 5 for y in the equation: 
16y = 4y + 60
16(5) = 4(5) + 60
Simplify.
16(5) = 4(5) + 60
80 = 4(5) + 60
80 = 20 + 60
80 = 80 (True).
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(2x + 3y = 12) x (-2)
(4x - 3y = 6) x 1
-4x - 6y = -24
4x - 3y = 6
You can cancel out the x values by adding the two equations together. 
(-4x + 4x) + (-6y - 3y) = (-24 + 6)
-9y = -18
y = 2
Solve for x now...
4x - 3(2) = 6
4x - 6 = 6
4x = 12
x = 3
Check... (x = 3, y = 2)
2(3) + 3(2) = 12 
6 + 6 = 12
12 = 12 <- this works! 
4(3) - 3(2) = 6
12 - 6 = 6
6 = 6 <- this works!
        
                    
             
        
        
        
Answer:
a/c and d/e are equal to cos(b)
Step-by-step explanation:
i used substitute and solve at first, but that didnt work too well so i moved on to the guess and check method. 
my guess is a/c and d/e are equal to cos(b), can anyone check this?
 
        
             
        
        
        
Answer:
sorry in dont know the ans
 
        
             
        
        
        
Step-by-step explanation:
Two factors that have a sum of 5 and a product of -66: 11 and -6.
x² + 5x - 66
= (x + 11)(x - 6).