Question 141572
60*40=2400 cm^2
Let x be the width of the matte.
(2x+60)*(2x+40)=4800
4x^2+200x+2400=4800
4x^2+200x-2400=0
4(x^2+50x-600)=0
(x+60)(x-10)=0
x=10 cm
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Ed