9x + 9x − 21 = 33

Please solve for x C:

Which equation and solution can be used to solve this problem? thirteen less than a number is sixteen. 13-n=16: add 13 to both sides. the answer is 29. n+13=16: subtract 13 from both sides. the answer is 3. n+16=13 subtract 13 from both sides. the answer is 3. n-13=16: add 13 to both sides. the answer is 29.

What is the best reason for jacinta to have a savings account in addition to a checking account

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?