To start, If possable I dont want any answers just methoulds or keywords to google in order to gain the nessary information to solve the problems.

Thing is our math/physics tutor got in a car accident a few months ago so his classes where called off, so we have been given our math test and well ive got no clue on some of this because we just did not get taught it.

Ive managed to work out the other 21 questions but these 4 just have me stumped big time, once again please if possable just an explination of how to do them would be great. Im not here just to be told an answer, lol.

Simplify the expression to $\displaystyle 4a^5 a^6 / (4a^4)^2$ to$\displaystyle (m / n) a^5 $where $\displaystyle m/n $is a factorisation expressed in its lowerst form

Express 7 SQRoot 13 in the form of SQroot n

Find the Angle (in degrees) between the Vectors: (3 -7) and (-8 -9) ***Dont know if this changes howthe question is worked out but the -7 is ment to be under the 3 as is the -9 ment to be under -8)

And the last question:

Solve $\displaystyle -2sin x^0 +3 =4$