The sum of twice a number and 5 is 21. What is the number?

Hello.

First, "twice a number" means we multiply 2 times that number.

Let the number be s.

Now, the sum of 2 times s and 5 is 21.

The product of 2 and s can be written like so:

Now, the sum of 2s and 5 is 21:

Subtract 5 from both sides:

Now, divide both sides by 2:

I hope it helps.

Have a nice day.

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below:

answer: r there any options?

step-by-step explanation: