Answer:
D
Step-by-step explanation:
Since triangles ABC and CDB are similar, CD and CB is the same as the ratio between CB and CA. 15:9=x:15. x=25. Subtracting CD to just be left with AD, we get 25-9=16, or answer choice D. Hope this helps!
 
        
             
        
        
        
Let the number of tie-dyed T-shirts = x
The man sold 4 times as many tie-dyed T-shirts as silk-screened shirts. 
So, the number of silk-screened shirts = 4x
He sold 180 shirts altogether
So,

So, the number of tie-dyed shirts = 36 
 
 
        
             
        
        
        
Answer:
=x^2+2x+5
Step-by-step explanation:
X^2+2x+5-0
=X^2+2x+5+0
Combine Like Terms:
=X^2+2x+5+0
=(X^2)+(2x)+(5+0)
=X^2+2x+5
Hope this helped!
 
        
             
        
        
        
Lets be a price of the calculator - $ a
then , after using the coupon, you need to pay $(a-18)
and after using 15% discount , you need to pay (1-0.15)a=0.85a
then, if 
(a-18) will be more than 0.85a, you should prefer 0.15 % discount, because it will be cheaper,
a-18> 0.85a
a-0.85a>18
0.15a > 18
a>120, that means that if the price of the calculator more than $120, 15% discount is better,
but if the price of the calculator is less than $120, you should choose $ 18 coupon.
for example, we have the price of the calculator $100
100-18=82,
100*0.85 =85, coupon is better.
If the price of the calculator $200
200-18=182,
200*0.85=170, so 15% discount is better
if price of the calculator is $120,
120-18=102
120*0.85=102, 
it will not matter, what you are going to use, because you are going to pay the same amount of money