(50 POINTS) Write out each sum.

Step-by-step explanation:

12. n^2+2n

if you insert 1 for k and then work up by inserting 2 for k and adding those together and stoping at n.

13. 8-2(2^n)

if you insert 3 for k and then work up by inserting 4 for k and adding those together and keep on going but stopping at n.

Hope that helps :)

3x + 18 = 147°

step-by-step explanation:

3x + 18 = 147°, because the value of the central angle is equal to the value of the arc formed by it.

i hope i you.

i can't solve unless i know what the line is

step-by-step explanation:

welcome to/p>