Show your work 20.5=15.5+(-3.6x)+1.8x a. -20 b. -2.7 c. 6.6 d. 20

Ok this is the same as 20.5 = 15.5 - 3.6x + 1.8x so first of all you add or subtract what u can on both sides in this case subract 3.6 and 1.8 because they both have a variable and 15.5 doesnt. (Since your subtracting you HAVE to line your decimals up the ONLY way you dont line your decimals up is with multiplication and division is another story.) it will look something like this
3.6
-1.8=
-1.8

Its negative because u have more negatives than positives.
now your equation will look like this
20.5 = 15.5 -1.8x
you bring the 15.5 to the other side so you subtract 12.5 into 20.5 look like this
20.5
-15.5=
5.0
you subtract because you are moving the 15.5 to the other side. and the answer is positive because there are more positives than negatives. So now the problem will look like this:
5.0=-1.8x
then you divide -1.8 on both sides to icilate your x you could use a cacultor. to get the anwser of x= -2.7