Answer:
C
Step-by-step explanation:
C
 
        
                    
             
        
        
        

The first step is to identify the order in which the equation must be solved, by following PEMDAS (you might know it as BEDMAS):
Parenthesis (or Brackets)
Exponents
Multiplication and Division
Addition and Subtraction
My advice would be to add parenthesis, following these rules, if you are not very good at finding them immediately by sight.
So:
![4 - 5 / 2 * (\frac{1}{10x})  = 1\\\\4 - [(5/2)*(\frac{1}{10x})]=1\\\\4-(2.5*\frac{1}{10x})=1\\\\4-\frac{2.5}{10x}-1=0\\3-\frac{x}{4}=0\\\frac{x}{4}=3\\x=3*4\\x=12](https://tex.z-dn.net/?f=4%20-%205%20%2F%202%20%2A%20%28%5Cfrac%7B1%7D%7B10x%7D%29%20%20%3D%201%5C%5C%5C%5C4%20-%20%5B%285%2F2%29%2A%28%5Cfrac%7B1%7D%7B10x%7D%29%5D%3D1%5C%5C%5C%5C4-%282.5%2A%5Cfrac%7B1%7D%7B10x%7D%29%3D1%5C%5C%5C%5C4-%5Cfrac%7B2.5%7D%7B10x%7D-1%3D0%5C%5C3-%5Cfrac%7Bx%7D%7B4%7D%3D0%5C%5C%5Cfrac%7Bx%7D%7B4%7D%3D3%5C%5Cx%3D3%2A4%5C%5Cx%3D12)
We check our answer:
![x=12\\4 - [(5 / 2) * (1/10)*(x)] = 1\\4 - [(5 / 2) * (\frac{1}{10}) * (12))] = 1\\4 - [2.5 * (\frac{1}{10})*12] = 1\\4 - [(\frac{2.5}{10})*12] = 1\\4 - [(\frac{1}{4})*12] = 1\\4 - 3 = 1\\1=1](https://tex.z-dn.net/?f=x%3D12%5C%5C4%20-%20%5B%285%20%2F%202%29%20%2A%20%281%2F10%29%2A%28x%29%5D%20%3D%201%5C%5C4%20-%20%5B%285%20%2F%202%29%20%2A%20%28%5Cfrac%7B1%7D%7B10%7D%29%20%2A%20%2812%29%29%5D%20%3D%201%5C%5C4%20-%20%5B2.5%20%2A%20%28%5Cfrac%7B1%7D%7B10%7D%29%2A12%5D%20%3D%201%5C%5C4%20-%20%5B%28%5Cfrac%7B2.5%7D%7B10%7D%29%2A12%5D%20%3D%201%5C%5C4%20-%20%5B%28%5Cfrac%7B1%7D%7B4%7D%29%2A12%5D%20%3D%201%5C%5C4%20-%203%20%3D%201%5C%5C1%3D1)
We are right!
So,  .
.
 
        
             
        
        
        
Answer:
B
Step-by-step explanation:
The equation  represents the total number of kittens, where
 represents the total number of kittens, where  represents <u>the number of weeks that have passed since Samantha started counting.</u>
 represents <u>the number of weeks that have passed since Samantha started counting.</u>
This means options C and D are false, because they say <u>the total number of kittens that have come into the shelter</u>.
 represents the number of weeks, weeks can be counted 0 weeks, first week, second week and so on, so option B is true (the domain is all whole numbers) because 0, 1, 2, 3, ... are whole numbers.
 represents the number of weeks, weeks can be counted 0 weeks, first week, second week and so on, so option B is true (the domain is all whole numbers) because 0, 1, 2, 3, ... are whole numbers. 
Number of weeks can't be a negative number. Since "real numbers" include negatives, therefore, we exclude option A.
 
        
             
        
        
        
Answer:
105/330 = 21/66 = 7/22
7/22 is the answer I think
Step-by-step explanation:
n(U) = 330
n(A) = 85
n(B) = 200
n(A n B) = 60
Now,
n(A U B) = n(A) + n(B) - n(A n B)
or, n(A U B) = 85 + 200 - 60
or, n(A U B) = 285 - 60 = 225
Now,
n(A U B) compliment = n(U) - n(A U B)
n(A U B) compliment = 330 - 225
so, n(A U B) compliment = 105
Now,
probability = 105/330
 
        
             
        
        
        
He had saved 320 initially
Step-by-step explanation:
Let the amount he saved be 'a' 
Amount spent = 20 + 40 + 30
= 90
His grand father gave 50
At the end he has 280
280 = a - 90 +50
a = 280 -50 +90
= 320
He had saved 320 initially