Well, for 4 I believe you must divide 2/4 by 100 to make it a decimal, then divide the decimal by the 5. :) Hopefully that is correct!
Answer:
x=15
Step-by-step explanation:
21-6=15
-4x+y=-5x-y=15
x+y=-y=15
x=15
157 degrees ... set 4x-5 = x+16 then solve, you should get x=7, plug in 7 for one of the equations and you'll get 23. subtract 23 from 180 and get 157. hope that helped :)