=25x2+y2+z2−10xy−2yz+10xz
Answer:
20,000 pairs of barber scissors.
Step-by-step explanation:
The sales volume <em>V</em> for barber scissors is directly proportional to the size <em>S</em> of the sales force and inversely proportional to the price <em>P</em> of the scissors.
In other words, we can write that:

Where <em>k</em> is the constant of proportionality.
19,440 pairs were sold in 2013, when there was 54 salespeople and the price was $20 a pair. Hence, <em>V</em> = 19440 when <em>S</em> = 54 and <em>P</em> = 20. Substitute and determine the value of <em>k: </em>

Hence, our equation is:

We want to determine the sales forecast with 50 salespeople and a price of $18 a pair. Hence, <em>S</em> = 50 and <em>P</em> = 18:

In conclusion, 20,000 pairs of barber scissors can be expected to be sold.
16,16 is the answer hope this helps and you get it right if wrong i am really sorry
the first question...the answer is 10
see;x is our unknown number
so;27-2=25
x + 15=25
x = 25-15
x =10
10 + 15 = 25
25 + 2 = 27