Hi!
1.)
a:A u B=

(The same elements are written once.)
b:A u C

c:B u C

Note:I used dots to mean commas .
Good work!
Answer:
X+4
Step-by-step explanation:
8+3x=25-x
3x+x=24-8
4x+16
(-2.8)+0+(-2.6)+6.4
-2.8-2.6+6.4
-5.4+6.4
1
Answer:
k=4
Step-by-step explanation:
First, we can subtract 3k on both sides. It is ultimately easier to start by subtracting the term with a variable. This would result in 45=5k+25. Then, we can subtract 25 on both sides to get closer to isolating k. This becomes 20=5k. We can then divide by 5 on both sides. This means that k=4.