Android : how to set in textview same sizes

I need to implement textview with equal sizes for 3 character, but i have got some problem if i add: This four buttons have got diferent sizes ...but i dont know why, and how can i change

MOD
_X_
_(_
_5_

_ is white spaces..

There is xml code:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="1dp" >

<TextView
    android:id="@+id/item_text"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"  
    android:textSize="12sp" >
</TextView>
<TextView
    android:id="@+id/item_text_Main"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"

    android:textSize="15sp" >
</TextView>

End there is picture of my problem: http://prntscr.com/49d6bo