A12×18 photograph is pasted in the center of a sheet such that there is a border around it with an equal width all around the picture. find the width of this border if it is known that the area of both the picture and the border is 280 cm².

To get the width of its border we must first find the area of the border.

Total Area - Area of photo = Area of border

280 - (12)(18) =  Area of border

 Area of border = 64 sq cm

We now have a rectangle with a hole of 12x18 , so now we cut the area of the border such that we will have 2 (18xW), 2 (12xW), and 4(WxW) squares.

by this info we will have an equation

64= 2(18xW) + 2(12xW) + 4(WxW)

simply

4W^2 + 60W = 64

We then solve for W

and it would be

W = 1 cm

 Hope my answer would be a great help for you.    

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Y= -2x-1 the negative in front of the 2 is because the slope is negative and the -1 is because it’s down 1 on the y axis.