Z=82 vertical or opposite angle theorem
15x-7 + 82=180 supplementary angles theorem
so 15x +75 =180
15x=180-75
x=105/15
x=7
I believe x=2 because 6x=2x+8
The answer would be 3n^2 + 2.
This can be found/proven by replacing "n" with term number (1,2,3,4...), then solving to get the final number. For example 3 * 1^2 + 2. You would first do 1^2, which is 1. Next, you would multiply 1 by 3, to get 3. Finally, you'd and the 2 to get 5. 5 is the 1st term, and you can use this same equation to get the rest of the terms you need.
I hope this helps!
1/2 of 40 is 20, and the question says 1/4 of the REMAINING cookies, and 1/4 of 20 is 5. There are 3/4 left, or 15 cookies. I hope this helps!
