3×(58÷2- 1)+2×3

=3×28+2×3

=84+6

=90 meters

3×(58÷2- 1) Calculate the distance from the first tree to the 29th tree, plus 2×3, because the trees at both ends of the road are still 3 meters away from the building, 3 meters at one end and 2×3 at both ends. I think it's easier to understand.

Properties of division operation

(1) If a number is divided by (or multiplied by) a number and then multiplied by (or divided by) the same number, the number remains the same. For example: 68÷ 17× 17=68 (or 68× 17÷ 17=68).

(2) A number divided by the product of several numbers can be divided by the factors in the product in turn. For example: 320÷(2×5×8)=320÷2÷5÷8=4.

(3) The quotient of a number divided by two numbers is equal to the number divided by the dividend in the quotient and then multiplied by the divisor in the quotient. For example: 56÷(8÷4)=56÷8×4=28.