1. 2(3x + 5) = 46

Question

4
5
6
7

2. 1/2x + 1/4x = 16

16
21.3
32
64

3. 6 - x - x = 18

-6
6
9
-9

4. 4x - 3/5 = 2/5

1/5
5/5
1/2
1/4

My answers:
1. 6
2. 21.3
3. ????
4. 1/4

I have no idea how to solve 3! Can you please explain? Thank you

Answer 1

6 - x - x = 18
6 - 2x = 18
-2x = 12
x = -6

check:

6 - (-6) - (-6) = 6+6+6 = 18

Answer 2

the others look good.
Can't imagine why #3 threw you. It's the most straightforward of them all.

Answer 3

6 - x - x = 18

-2x = 12

x = -6

Your answers are correct.

Answer 4

Thank you! That helped a lot! I have no idea why 3 was hard for me...