The length of a rectangle is 9 inches more than three times the width. the perimeter is 98 inches. find the length and width

1. what are the missing reasons in the proof 2. it's in the second picture and 3

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

What is the absolute value of the complex number -4-sqrt2i