Book Maths Puzzle Algebra

Solve
3x-2y-6z=-4
-3x+2y+6z= 1
x- y -5z=-3

Read Solution (Total 1)

Book Other Question

Solve
x- 3y+ 2z=18
5x-13y+12z=80
I need to know what degrees these would be, im making a pie chart..

33.3% ,30% ,13.3% ,23.3%

or just tell me how to do it - I thought you multiply by 360 and move the decimal 2