Then number is 3 because 3 times 5 is 15 and 15 plus 2 is 17. Hope this helps.
A= 30ft, because you only have to multiply LxW= A that is equal to 2x15=30ft
Use Pythagorean theorem:
9i-j = sqrt (9^2 - 1^2) = sqrt(81-1) = sqrt80
now divide both terms in V by that:
u = 9/sqrt(80)i - 1/sqrt(80)j
see attached picture:
(45 - 32) / 9 * 2
13 / 18
the. answer is 13 / 18