x=15 y=-2
Step By Step:
Step 1: solve for x in the second equation (x-2y=11) x=11+2y
Step 2: Substitute this value of x into the first equation (2x+9y=-4) giving you 2(11+2y)+9y=-4
Step 3: distribute the 2 throughout the parentheses giving you 22+4y+9y=-4
Step 4: simplify each side giving you 22+13y=-4
Step 5: solve for y (subtract 22 from both sides then divide by 13) giving you y=-2
Step 6: substitute this value of y into either equation (I used x-2y=11) giving you x-2(-2)=11
Step 7: solve for x (multiply -2 by 2 and add this value to both sides) giving you x=15