
Now, we can just multiply it and obtain the result

I used law presented on this example
Answer:
c = -1
Step-by-step explanation:
3(c+5)=12
3 × c = 3c
3 × 5 = 15
3c + 15 = 12
<u> - 15 -15</u>
3c = -3
c = -3 ÷ 3 = -1
Check:
3(-1+5)=12
-3 + 15 = 12
The LCD of 3 and 4 is 12. To make 4 into 12, we multiply it by three, so 3 would also have to be multiply by 3, turning 3/4 into 9/12.
The same thing applies to 1/3, only it needs to be multiplied by 4. So it would become 4/12
9/12 - 4/12 = 5/12