A. You may set the variables in either order. But for argument sake, let's set as follows:
x = Amount of bookshelves
y = Amount of tables
B. Because of the amount of things you need to make, the following is an inequality using those variables.
x + y > 25
Plus you can determine a second inequality based on the amount of money that you have to spend.
20x + 45y < 675
Finally you may also add in that each value must be greater than or equal to zero, since they cannot have negative tables.
C. By solving the system and looking at basic constraints when graphed, you can see the feasible region has 4 vertices.
(0,0)
(18, 7)
(0, 15)
(33.75, 0) or (33, 0) if you insist on rounding.
45 × 13 = 585
Which is exactly how much he'd need to pay back his sister and buy the bike. So, it would take him 13 weeks.
Answer:
3520 ft/min
Step-by-step explanation:
40 mi/h = (40 mi/h)×(5280 ft/mi)×(1 h)/(60 min) = 3520 ft/min
_____
Each conversion factor has a value of 1 (numerator = denominator), so changes the units without changing the speed.
Answer:

Step-by-step explanation:
Given that,
The frequency of x-rays, 
We need to find the wavelength for x-rays. The relation between wavelength, frequency and speed of light is given by :

So, the wavelength for x-rays is
.