Answer:
2A/h - a = b
Step-by-step explanation:
Using A= 1/2(a+b)h
Divide both side by h
⇒A/h = 1/2(a + b)
Mutiply both sides by 2
⇒2A/h = a + b 
Take the 2 over to the other side
2A/h - a = b
Keep in mind, that the (a) is not on the bottom, rather on its own
 
        
             
        
        
        
All you do is divide. 
330/390= 0.846
round it: 0.85 
Answer is about 85%
        
             
        
        
        
8 Ounces of shampoo for $0.89
        
             
        
        
        
Answer:
270 words per minute
Step-by-step explanation:
It is given 180 words in 2 minutes, this means Toni can type 180/2 = 90 words per minute (90wpm).
Thus, in the same ratio/rate, Toni would be able to type:
90 * 3 = 270 words per minute.
Correct answer 270 wpm