Answer:
x = -1.142857
Step-by-step explanation:
Start by distributing the 3/2 in the parentheses.
3 = 10.5x + 15
Next, get the variables on one side. There are a few way to do this, the easiest being to subtract 15 from both sides.
-12 = 10.5x
Now you need to get the variable alone. Do this by dividing both sides by 10.5.
-1.142857 = x
Hope this helps you out.