Respuesta :
You can write this as an equation. So let n be the number. Two ninths of the number is just (2/9)n, so the equation is...
(2/9)n + 17 = 21
(2/9)n = 21 - 17
(2/9)n = 4
n = 4/(2/9)
n = 4 * 9/2
n = 36/2
n = 18
So the number is 18.
The unknown number is 18 and this can be determined by using arithmetic operations and by forming the linear equation in one variable.
Given :
The sum of two-ninths of a number and 17 is 21.
The following steps can be used to determine the unknown number:
Step 1 - Let that unknown number be 'a'.
Step 2 - Now, form the linear equation according to the given data.
[tex]\dfrac{2}{9}n+17=21[/tex]
Step 3 - Subtract 17 on both sides in the above equation.
[tex]\dfrac{2}{9}n +17-17=21-17[/tex]
[tex]\dfrac{2}{9}n=4[/tex]
Step 4 - Cross multiply in the above equation.
[tex]n = \dfrac{4\times 9}{2}[/tex]
n = 18
So, the unknown number is 18.
For more information, refer to the link given below:
https://brainly.com/question/2263981
