What number should be added to both sides of the equation to complete the square? x-^2+8x=4

What expression is equivalent to 42x-56y

What is the 9th term in the geometric sequence described by this explicit formula? an=-6. (2)(n-1) apex

Can someone me immediately, this is due by midnight! if you can't see the question, i'll text it to you. show the steps you took to get your answer.