7(2 + 6 – 4d) = pl help me I don’t get it

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Apool measures 12.3 feet by 16.6 feet. if the longer wall of the pool has a diagonal of 17.8 feet, what is the volume of the pool? (round to nearest tenth)

In the figure below, m∠r is 60°, and m∠t is 120°. what is m∠q? a. 60° b. 30° c. 120° d. 54