Grandpa Zhang’s house used 83 kWh of electricity in July, 1.4 kWh less than in August. In August, I used X kilowatt-hours of electricity. (List the equations according to the quantitative relationship in the question, and find the solution of the equations)
张爷爷家七月份用了83度电，比八月份少用1.4度电．八月份用了X度电．(根据题中的数量关系列出方程，并求出方程的解)
<gadget id="calculator">83 + 1.4</gadget>
<output>84.4</output>

<result>84.4</result>