Question

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Answer 1

Answer:

23

Step-by-step explanation:

-The length of the cubes side is (x-5) and the total surface area is 1944 sq units.

-We apply the formula for surface area and equate to solve for x:

$A=6s^2\\\\1944=6(x-5)^2\\\\324=(x-5)^2\\\\324=x^2-10x+25$

#Equate to zero as below:

$324=x^2-10x+25\\\\x^2-10x+25-324=0\\\\x^2-10x-299=0\\\\\# Quadratic \ Formula:\\\\x_{1,2}=\frac{-b\pm \sqrt{b^2-4ac}}{2a}\\\\\\=\frac{10\pm\sqrt{(-10)^2-4(1\times-299)}}{2\times1}\\\\x_1=23, \ \ \ x_2=-13$

length dimensions are always positive.

Hence, the value of x is 23