First one simplifies to 2x + 6 = 2x + 7 which can't be true so this one has No Solution.
Same applies to the second equation ( 5x + 15 = 5x - 15) No solution
also the last one has no solution because it simplifies to 4x + 20 = 4x + 19
Answer:
First then second answer below
Step-by-step explanation:
-x+y 4
-1/-1=1 x=1 y=1
y/1=1/1+4/1
y=1x+4
-x+7y 21
-1/-1=1
7y/7=1/7+21/7
y=1/7x+3
-1, -1 I think is the answer
If they have the same charge
x+x+x+x+x+x+x=-42
7x=-42
x=-6
so to check our answer
-6-6-6-6-6-6-6=-42
-12-12-12-6=-42
-24-18=-42
-42=-42
