after adding which two square numbers the answer is 400

Answer 1

Hi! Approaching this problem, we know we'll need to get numbers whose squares are pretty big, so we can get to 400.

Let's test a random number:

25 * 25 = 625 Way too big! We'll need to try smaller.

15 * 15 = 225 Could be promising.

Let's see if it is the right answer by testing if we can add it with another square number to get to 400.

400 - 225 = 175

Is 175 square? The square root of 175 is 13.2, so it is not a square number. We now know 15 is not right.

Let's try another number using the same method:

16 * 16 = 256

400 - 256 = 144

The square root of 144 is 12, so it is a square number!

So we now know 144 is a square number, 256 is a square number, and they add together to get 400.

So our answer is:

144 + 256