At the beginning of the season, MacDonald had to remove 5 orange trees from his farm. Each of the remaining trees produced 210 oranges for a total harvest of 41790 oranges.

Write an equation to determine the initial number of orange trees (t) on MacDonald's farm.

Let t be the initial number of orange trees on MacDonald's farm.

After removing 5 trees, the number of remaining trees is t - 5.

Each remaining tree produced 210 oranges, so the total number of oranges produced by the remaining trees is (t - 5) * 210.

The total harvest of oranges is 41790, so we can write the equation:

(t - 5) * 210 = 41790

Simplify the equation:

210t - 1050 = 41790

Add 1050 to both sides:

210t = 42840

Divide by 210:

t = 204

Therefore, the initial number of orange trees on MacDonald's farm was 204.