Please help you will get brainliest and 5 stars please hurry this is due very soon and I have so much more work to do

Which matrix can be multiplied to the left of a vector matrix to get a new vector matrix ?

Simplify 5 square root of 7 end root plus 12 square root of 6 end root minus 10 square root of 7 end root minus 5 square root of 6 . (1 point) 5 square root of 14 end root minus 7 square root of 12 5 square root of 7 end root minus 7 square root of 6 7 square root of 12 end root minus 5 square root of 14 7 square root of 6 end root minus 5 square root of 7

Find the length of the normal and the angle it makes with the positive x-axis. (see pictured below)