I DONT NEED ANSWERS (but that would be nice) I JUST NEED AN EXPLANATION PLEASE ​

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.

Factor and solve to find roots x squared -x - 90 =0

Write the equations in logarithmic form 10^3=1,000