Analog Computer Wiring
Your circuit is way too complicated. You need to study how an inverting gain op amp circuit works. Once you understand, the gain for voltage on the left side of R6 is -1 (-R3/R6) and the gain for voltage on left side of R2 is -10 (-R3/R2).

You can eliminate everything other than OA1, R3, R2 and R6.  R2 and R6 will connect directly to Y and X power supplies.

The gain of the resulting circuit will be -R3/R6 * x + -R3/R2 * y.

Now rearrange original equation to -kax + -10bky.

R6 = R3/ka and R2 = R3/10bk