Answer:
If it a khan you can go take a hint and try to find it
Answer:176 psychology textbooks and 98 Biology textbooks were sold.
Step-by-step explanation:
Let x represent the number of psychology textbooks that were sold.
Let y represent the number of biology textbooks that were sold.
textbook store sold a combined total of 274 psychology and biology textbooks in a week. This means that
x + y = 274 - - - - - - - - - - -1
The number of psychology textbooks sold was 78 more than the number of biology textbooks sold. This means that
x = y + 78
Substituting x = y + 78 into equation 1, it becomes
y + 78 + y = 274
2y = 274 - 78
2y = 196
y = 98
x = y + 78 = 98 + 78
x = 176
Answer: 
Step-by-step explanation:
Given : Number of choices for novels = 4
Number of choices for plays = 6
Number of choices for poetry books = 5
Number of choices for nonfiction books = 5
Total books =4+6+5+5=20
If he wants to include all 4 novels, then the number of books left to select = 9-4=5
Remaining choices for books = 20-4=16
Number of combinations of n things taking r at a time : 
Then, the number of different reading schedules are possible :_
Hence, the required answer is .
Ok so basically.... 15^2= 9^2+ x^2
15*15
225= 81+x
-81. -81
144=x^2
12=X
Im pretty sure it’s right!
I used the formula A^2+B^2=C^2
Mars<span> and Earth orbit the </span>sun<span> at different speeds: Earth has an inside track and gets around the sun more quickly. Plus, both have elliptical orbits, rather than perfect circles. So the distance to Mars from Earth is constantly changing. In theory, the closest the planets could come together would be when Mars is at its </span>closest point<span> to the sun (</span>perihelion) and Earth is at itsfarthest point<span> (</span>aphelion<span>). In that situation, the planets would be 33.9 million miles (54.6 million kilometers) from each other. But that has never happened in recorded history. The closest known approach was 34.8 million miles (56 million km) in 2003 ....... :D!
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