Which of the following affected from the expression 18+ 12

When keisha installed a fence along the 200 foot perimeter of her rectangular back yard, she left an opening for a gate.in the diagram below, she used x to represent the length in feet of the gate? what is the value? a. 10 b. 20 c. 25 d. 30

Laura read 1/8 of a comic book in 2 days. she reads the same number of pages every day. what part of the book does she read in a week

The maximum distance (in nautical miles) that a radio transmitter signal can be sent is represented by the expression 1.23h√, where h is the height (in feet) above the transmitter. estimate the maximum distance x (in nautical miles) between the plane that is receiving the signal and the transmitter. round your answer to the nearest tenth.