Maths Geniuses and Experts,.. I'm confused I NEED you HELP.?

Question

I won't hesitate to give you the ten points if you sovle number one which i keep getting lost as i try to do. And if you also sovle number two. Pls i really need your help. I appreciate any help you give to me.

1. List all four-element subsets of Z.
Z =
{b; c; d; e; f}

2. The supplement of an angle is 4 degree more than three times the angle. Find the angle.

Answer 1

1. start with leaving out the last element and slowly move over. like this. {b, c, d, e} {b, c, d, f} {b, c, e, f} {b, d, e, f} and then {c, d, e, f} just go through and write it out 5 times ( 5 objects choose 4 = 5C4 = 5) and then put an X through a different element in each line.
b c d e X
b c d X f
b c X e f
b X d e f
X c d e f

see?

2. supplement = 180 - angle
call angle a
is means that's where the = goes
180 - a =
more means put + 4 at the end
3 times the angle = 3 * a = 3a
so 3a + 4
so 180 - a = 3a + 4
176 = 4a
44 = a

Answer 2

1. {b,c,d,e} , {b,c,d,f} , {b,c,e,f} , {b,d,e,f} , {c,d,e,f}

2. The angle is (180 - 4)/4 = 44 degree
You can solve with equation : Say the angle is a then the supplement is 180 -a
180 - a = 4 + 3a
4a = 180 - 4
a= 44 degree