Hey there!
Your answer would be -32.5.
First, you would multiply both sides by 10, and simplify. That would bring you to 4x + 25 = 2x - 40. Now you can start isolating the varible. Subtract 25 from both sides, and simplify. That gives you 4x = 2x - 65. Next, subtract 2x from both sides, and simplify once again. That brings you to 2x = -65. Finally, divide both sides by 2 and once more, simplify. It gives you your answer x=-65/2 or -32.5
