B) 29
Because 20^2+21^2=c^2
Answer:
C; A singleton set
Step-by-step explanation:
Mathematically, when a number is non-negative; it is either positive or zero
Now, this is because 0 identifies as neither a positive or a negative number
hence, when we find the difference between the two sets, the only number that stands out unmatched is the value 0
What this mean is that we are having a set with a single number result
So we have our answer as {0}
Which is a singleton set
Answer: No, they are not.
Step-by-step explanation: To see if ratios are equivalent, you have to simplify them. 6:4 can be simplified to 3:2 but 19:12 cannot be simplified anymore. Since 3:2 is not equal to 19:12, they are not equivalent.
Answer:
5
Step-by-step explanation:
The correct first step to solving the system of equations in the most efficient manner is x = -4y +19.
The given system of equations is;

<h2>What is the first step to solving an equation?</h2>
The first step would be to rearrange the variables in the second equation so we have a defined expression for x.
We would want to do this so we could then plug in the defined expression for x into the other equation and solve for the other variable.
x + 4y = 19
Rearrange this by getting the 4y to the other side.
We can get 4y on the other side by subtracting 4y from both sides
x + 4y - 4y = 19 - 4y
x = -4y + 19
Hence, the correct first step to solving the system of equations in the most efficient manner is x = -4y +19.
To know more about the System of equations click the link given below.
brainly.com/question/15240525