Hello please help me

1. How many arithmetic operations (total of additions, subtractions, multiplications, divisions) are required to do each of the following? Answer using big-O notation (for example, O(n log n)); you don't need to show constant factors or lower-order terms. la. Compute the sum of two n-vectors? 1b. Compute the product of an n-by-n matrix with an n-vector? 1c. Compute the product of two n-by-n matrices? 1d. Solve an n-by-n upper triangular linear system Ur=y