Find an inverse for 43 modulo 660. that is, find an integer s such that 43s=1(mod 660)

Matt and brian were solving a system of equations. they both noticed that the two lines had the same slope. brian said that because each line in the system had the same slope, the two lines had to be parallel, which meant the solution to the system was "no solution" matt disagreed, and said they should also look at the y-intercepts before determining how many solutions there were. who is correct?

For the following geometric sequence, find the recursive formula. {-80, 20, -5, } i need : ')

What is the simplified form of square root of 400 to the 100th power ?