<h3>
Answer: n = 9</h3>
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Explanation:
Let's assume that n is not negative. If we tried the smallest nonnegative value, n = 0, then we get
- 30+n = 30+0 = 30
- n/3 = 0/3 = 0
- sqrt(n+16) = sqrt(0+16) = 4
The middle result 0 isn't a natural number. The set of natural numbers is {1,2,3,4,...} which is the set of positive whole numbers.
So we can't use n = 0.
Through trial and error, you should find that n = 9 is the next value we can try such that sqrt(n+16) is a natural number, and so is n/3.
If n = 9, then,
- 30+n = 30+9 = 39
- n/3 = 9/3 = 3
- sqrt(n+16) = sqrt(9+16) = 5
We see that the middle result is now larger than 0 and it's a natural number. The same can be said for the last result as well.
With the information given we can wirte down 2 different equations where:
x = How many Fictoon books there are
A nd y = How many non-fiction books there are :
#1) x + y = 312
( The total of the books is 312 )
#2) x = 11y
(He has 11 times as many firction books as he has non-ficton books)
Now what we need to do is to isolate one the variables ( x or y ) , get its value and apply to one the equations to get the other variable's value:
We can do that by the property of substitution:
If x = 11y
then x + y = (11y) + y = 12y
If x + y = 312
and x + y = 12y
then 12y = 312
Now with the equation 12y = 312 , we can isolate y by dividing both sides of the equation by 12 :
12/12y = 312/12
y = 26
What that means : Mark has 26 non-fictional books.
Now that we have the value of y , we can find the value of x by plugging y to one of the equations :
x + y = 312
or
x = 7y
( I will do both , but you dont need to )
x + y = 312
Plugin 26 for y :
x + 26 = 312
Shift 26 to the other side of the equation by subtracting both sides of the equation by 26:
x + 26 - 26 = 312 - 26
26 - 26 cancel out , so we end up with :
x = 286
Second Equation :
x = 11y
Plugin 26 for y:
x = 11 × 26
x = 286
Awnser : Mark has 286 fictoon books and 26 non-fiction !
I hope you understood my brief explanation. And please consider marking this awnser as Branliest. Thank you ! :)
Answer:
x=9
Step-by-step explanation:
2x+10=28
2x=18
x=9
<em>It took about 2.05 hours!
its already round to the nearest hundredths of an hour
</em>
