Final answer:
The equivalent fraction for the number of houses with 4 or more trees is 3/20, which is found by simplifying the original fraction 6/40.
Step-by-step explanation:
The fraction of houses in a city that have 4 or more trees is 6/40. To find an equivalent fraction, we need to simplify the given fraction by dividing both the numerator and the denominator by their greatest common divisor. In this case, we can simplify the fraction by dividing both numbers by 2.
6 ÷ 2 = 3
40 ÷ 2 = 20
Therefore, the equivalent fraction for the number of houses with 4 or more trees is 3/20. This simplified fraction expresses the same value as the original fraction 6/40.