I am trying to use mathematica to verify a math problem which is a double integral:
$$\int \int\_D (3x+4)^4 \delta x\delta y$$
with $$0 \leq x \leq 4, 0 \leq y \leq 4,$$
I tried the following:

-drawing function:

```
f[x_, y_] := (3 x + 4 y)^4; R = ImplicitRegion[{0 < x < 4, 0 < y < 1}, {x, y}]; Plot3D[f[x, y], {x, y} \[Element] R]

```

And then writing a double integral in mathematica with the escape hotkey.

```
\!\( \*SubsuperscriptBox[\(\[Integral]\), \(0\), \(4\)]\( \*SubsuperscriptBox[\(\[Integral]\), \(0\), \(1\)]f[x, 
    y] \[DifferentialD]y \[DifferentialD]x\)\)

```

I tried as well:

```
Integrate[f[x, y], {x, 0, 4}, {y, o, 1}]

```

The first attempt gives me output 32, and the second gives me output:

```
-(512/5) (-374 + 162 o + 135 o^2 + 60 o^3 + 15 o^4 + 2 o^5)

```

Can you please help?