let x be the increase , assuming we increase only on one side.
(10+x)(8+x) = 1.75(80)
80 + 18x + x^2 = 140
x^2 + 18x - 60 = 0
let's complete the square ...
x^2 + 18x + 81 = 60+81
(x+9)^2 = 141
x+9 = ±√141
x = appr 2.87 cm or some inadmissible negative
the new dimension is 12.87 cm by 10.87 cm
check:
new area = 12.87..(10.87..) = 140
(I carried the full answer in my calculator)
which is a 75% increase
A photo measures 10cm by 8cm. if you wish to increase each picture of the side uniformly by such that the area increased by 75%, what will the new dimensions be
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