Arectangle is 50 feet by 60 feet. if both the width and the length are increased by the same amount, the area is increased by 1,200 square feet. find the dimensions of the new rectangle. which of the following equations represents the word problem? 50 + x + 60 + x = 1,310 (50 + x)(60 + x) = 4,200 (50 + x)(60 + x) + 1,200 = (50)(60)