One less than twice a number is seventeen.
It can help because 9×4 =36, and 9×8=72. if you divide 72 by 2 you get 36 which is the answer to 9 ×4. basically because nine is the same in both problems you are multiplying by 4 (and you know 4 is half of 8) you can assume that multiplying the sum of 4 and 9 that you will get the sum of 8 and 9.
I’m hoping this helps (but hopefully now you can give the brainliest to the person above)
I’m not very familiar with the square roots method but I believe you try and isolate the term that is squared.
Answer:
Answer will be 
Step-by-step explanation:
We have to perform the calculation
without changing into decimal
can be written as 
So 
Now taking
common
