# Solving for $v_{out}$ in this circuit

Assuming ideal op-amplifiers, I did the following steps:

$v_{out1}=v_1\frac{R_2}{R_1}=2v_1$

$v_{out2}=v_o=\left(\frac{v_{out1}}{R_3}+\frac{v_2}{R_4}\right)R_5=4v_1+2v_2$

My textbook claims $4v_1-2v_2$

• There are 2 things you need to know here. The correct transfer function for an inverting opamp, and how to apply superposition. – efox29 Oct 9 '15 at 0:03
• I know the transfer function, and I am aware of the superposition theorem, but I'm not sure if I've done that step correctly, considering my answer comes out right except for a minus sign on the second term. – B. Lee Oct 9 '15 at 0:05
• Vout1 is not 2Vi. Transfer function is wrong. – efox29 Oct 9 '15 at 0:07