To divide f(x) by d(x), we need to perform polynomial long division:
```
_________
x + 3 | x³ + 4x² + 7x - 9
```
To start the division, we divide the highest degree term of f(x) by the highest degree term of d(x), which gives us x². We then multiply x² by d(x), which is x + 3, and subtract it from f(x):
```
x²
__________
x + 3 | x³ + 4x² + 7x - 9
- (x³ + 3x²)
__________
x² + 7x - 9
```
Now we repeat the process with the new polynomial x² + 7x - 9:
```
x² + 7x
__________
x + 3 | x³ + 4x² + 7x - 9
- (x³ + 3x²)
__________
x² + 7x - 9
- (x² + 3x)
__________
4x - 9
```
We are left with the remainder 4x - 9. Therefore, R(x) = 4x - 9.