To answer this question, you should combine like terms:
Like terms are two or more terms that share the same variable.
J is the variable in this question so add 0.9j to both sides of the equation to get j on one side:
-0.1j + 0.8 = 0.76
Now subtract 0.8 from both sides to isolate j on one side of the equation:
-0.1j = -0.04
Divide both sides by -0.1 to isolate j and your answer should be:
Answer: j = 0.4