The sum of the digits of a certain two digit number is 3. when you reverse its digits you decrease the number by 9. what is the number

21

Step-by-step explanation:

Find out all the combinations

3      0 + 3 = 3                             Reversed  30  

12      1 + 2 = 3                                               21

21      2 + 1 = 3                                                12   <

30     3 + 0 = 3                                                3

Then consider what the Question is Asking

And apply it to each of the combinations

Then Use trial and error to find the answer

step-by-step explanation:

problem:

f(x) = - 2/3x + 5; f(5/2)

substitute 5/2 in for x:

f(5/2) = -2/3(5/2) + 5

simplify the right side:

f(5/2) = -5/3 + 5

f(5/2) = 10/3

f(5/2) = 10/3

i hope this !