Respuesta :
Answer:
x=10
Step-by-step explanation:
according to the question
(x+2)(x-2)=96
=>x^2-4=96
=>x^2=96+4
=>x^2=100
=>x=√100
Therefore
x=10
x=-10
As width and length can't be negative
So x=10
Width=10-2=8
Length=10+2=12
12×8=96 (proven)
Answer:
Please check the explanation.
Step-by-step explanation:
As we know that the area of a rectangle is defined by multiplying the length by the width.
- [tex]A=l\times w[/tex]
Given
- rectangular frame length = l = (x+2) units
- rectangular frame width = w = (x-2) units
- Area = 96 square units
substituting all the given values in the formula to find the value of x.
[tex]A=l\times w[/tex]
[tex]96=\left(x+2\right)\times \left(x-2\right)[/tex]
[tex]96=x^2-4[/tex]
[tex]x^2-4=96[/tex]
subtract 96 from both sides
[tex]x^2-4-96=96-96[/tex]
[tex]x^2-100=0[/tex]
[tex]x^2=100[/tex]
[tex]\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}[/tex]
[tex]x=\sqrt{100},\:x=-\sqrt{100}[/tex]
[tex]x=10,\:x=-10[/tex]
Putting x = -10 in the length and width will make the length and width negative, which can not be possible.
i.e.
length = l = x+2 = -10+2 = -8 units
width = w = x-2 = -10-2 = -12 units
Therefore, x=-10 must be excluded.
Now, putting the length of x = 10.
i.e.
length = l = 10+2 = 10+2 = 12 units
width = w = x-2 = 10-2 = 8
[tex]A=l\times w[/tex]
96 = 12 × 8
96 = 96
Therefore, the correct value of x = 10