How to scale +15v/-15v signal to +10v/-5v?
Schematic:



LTSpice Simulation:



Calculations:

R5 = R7 (For gain = 1) = 10k (Reasonable common value)

R3 || R4 = R1 || R2 = 10K (For equal equiv. resistors, gain = 1, no DC gain)

15 * R4 / (R3 + R4) = 2.5 (For the voltage offset)

R1 = R2 (To divide input by 2)