Answer:
It's a square
x = 26/5
Step-by-step explanation:
Well, since all the sides are equal (shown by the 3 lines in the sides) and all the angles are 90 degrees (show by the little squares in the corners), I believe the shape is a square.
Because the sides are equal, you would set up the equation by making the two expressions equal to each other:
3x + 11 = 8x - 15
The next step is to get the variable (x) on only one of the sides. You can do this by subtracting 3x from both sides or by subtracting 8x from both sides. I will subtract 3x here just so the new number can be positive, but either will work.
3x + 11 = 8x - 15
-3x -3x
0 + 11 = 5x - 15
Now, you isolate the x by adding 15 to both sides. Remember, whatever you do to one side, you must also do it to the other side of the equal sign.
11 = 5x - 15
+15 +15
26 = 5x
Lastly, get rid of the number in front of the x so that x is alone on a side of the equal sign. You do this by dividing both sides by 5.
x = 26/5
Now, you can either make this into a mixed number or a decimal or keep it how it is. I hope this helps :]