Solve the missing variable. show your process because i did the other three on my homework sheet but i really struggle with math. will definitely give because this means a lot : )-8.4b - 4.2 = 12.6is this -2 or?

The big intention behind every step you take in these "find the value of x" problems is to isolate the x by doing PEMDAS in reverse and using the opposite operation. So I would do first is add the 4.2 on both sides. This is so that the 4.2 on the side of the x is canceled out. This makes

From here, since the opposite of multiplying is dividing, you divide both sides by -8.4. You can use a calculator to find the answer but you get