activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/myDisplay"
        android:layout_width="361dp"
        android:layout_height="86dp"
        android:layout_marginTop="36dp"
        android:gravity="center"
        android:text="Display"
        android:textSize="36sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.32"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/myBtn"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="16dp"
        android:text="Button"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent" />

    <EditText
        android:id="@+id/inputA"
        android:layout_width="157dp"
        android:layout_height="58dp"
        android:layout_marginEnd="28dp"
        android:ems="10"
        android:hint="Enter A"
        android:inputType="numberDecimal"
        app:layout_constraintBottom_toTopOf="@+id/myBtn"
        app:layout_constraintEnd_toStartOf="@+id/inputB"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/myDisplay" />

    <EditText
        android:id="@+id/inputB"
        android:layout_width="157dp"
        android:layout_height="58dp"
        android:layout_marginEnd="16dp"
        android:ems="10"
        android:hint="Enter B"
        android:inputType="numberDecimal"
        app:layout_constraintBottom_toTopOf="@+id/myBtn"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/myDisplay"
        app:layout_constraintVertical_bias="0.501" />
</androidx.constraintlayout.widget.ConstraintLayout>