What is the value of the 30th term in the following arithmetic sequence 12,6,0,-6

Anyone know? will mark brainliest if you're correct!

The spring the owner of a sporting good store decreases the price of winter gloves from $10 to $8 each increases the price of swimming goggles from $8 to $10 without doing the math you think the percent decrease in the price of the gloves the same as the percent increase of the goggles explain why or why not

Two planes leave an airport at the same time, one flying east, the other flying west. the eastbound plane travels 20 mph slower. they are 1600 mi apart after 2 hr. find the speed of each plane.