Set 7x-4 and 31 equal to each other
7X-4=31
Add four to both sides
7X=27
X=3
The answer is D
Sarah wants to buy a carpet for a square room with an area of 400sq ft.
the length of the room is 20ft.
Area is a quantity that describes the extent of an area on a plane or curved surface. The area of a planar region or planar region refers to the area of a shape or planar layer, and surface area refers to the area of an open surface or boundary of a three-dimensional object. Wikipedia
The area is the area occupied by a two-dimensional figure. That is, it is a quantity that measures the number of unit squares that cover the surface of a closed figure. The standard unit of area is the square unit, commonly expressed in square inches, square feet, and so on.
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Area= a*height
the formula for an isosceles trapezoid is 1/2(base1+base2)*height. 1/2 base 2 and 2a will simplify to a base length of a. a times height or a*height
