We have trapezoid with congruent legs.
30x + 11y = 2x + 3
28x +11y = 3
Also we have
30x + 11y = 12
We got 2 equations:
30x + 11y = 12
28x +11y = 3 (*-1) -----> -28x -11y = -3
30x + 11y = 12
-28x -11y = -3
2x = 9
x=9/2
30x + 11y = 12 ------> 30*9/2 +11y =12 ------> 135+11y =12, ---> 11y = - 123,
y= - 123/11
