Hello There!
The length of the hypotenuse is 10.
We know what 2 sides are 6 and 8.
To find the third side we use the formula a^2 + b^2 = c^2
So we multiply 6 by 6 which equals 36 and then multiply 8 by 8 which equals 64.
Next we add 64 and 36 together and we get 100.
Next, we square root 100 and get 10.
10 is the length of the hypotenuse.
It will be 4f-30. Using substitution, you get (-8f-12) + (12f-18). Adding this together you get -8f-12+12f-18. Then you add -8f and 12f to get 4f, and add -12 and -18 to get -30.
Your answer is 26,453
Although I don't feel as if this is a homework question, I will still show the work.
Work:
Step 1: 999 + 999 = 1,998
Step 2: 1,998 + 999 = 2,997
Step 3: 2,997 + 23,456 = 26,453
Hope I was able to help! :)