The value of x would be 9.
As we already know, a variable is an unknown number, so a number beside a variable, is basically multiplying the 2 numbers. Now lets replace y with 6.
2x+3X6=36. Well 3X6 is 18, so 2x+18=36. Now we can reverse backwards.
36-18=18, so something times 2 is 18, 18 divided by 2 is 9. 2X9+3X6=36