)determine elementary matrices e1, e2, e3 of type iii such that e3e2e1a = u with u an upper triangular matrix. the matrix e1 should turn the element in position (2,1) into a 0. enter this matrix in matlab as e1 using commands similar to the ones in example 1. the matrix e2 should turn the element in position (3,1) into a zero. enter this matrix in matlab as e2. note that to zero out the entries in column 1, you need to add or subtract a multiple of row 1. once you have found the matrices e1 and e2, compute the product e2e1a in matlab. use format rat so that the entries will be given as fractions. based on the result, determine the matrix e3 that turns the

For question 1, i'm a bit stuck between serif fonts or large enough type to read. serif fonts are good fonts to use because their easy to read. but you also need your type be large enough to read. if i had to say what you need to consider most important, i would say d is the answer.  for question 3, i believe the answer is d. it seems most appropriate to do that. on every page or every other page would be too much, and only on the contact page just seems inappropriate.  for question 4, it's probably a. by "color scheme" it doesn't mean just one color, but a set of colors. colors that are complimentary to each other. having too many is too distracting so it's best to limit it as much as possible, but not to the point where your website looks dull.hope this !