Answer:

Step-by-step explanation:
The answer would be
because
= 
Hello,
A(x)=x²-x-72 (m²)
L=(x+8) (cm)= (x+8)/100 (m)
We suppose here x≠-8
(in reality x²-x-72>0 ==>x<-8 or x>9
but x+8>0 ==> x>-8
then
only x>9 are solutions)
W=A(x)/ ((x+8)/100 )=100*(x²-x-72)/(x+8)= 100*(x-9)(x+8)/(x+8)=100*(x-9)
Answer:
Answer ::+-6
Step-by-step explanation:
x:3=12:x
or, x/3 = 12/x
Doing cross multiplication,
x^2=36
Putting sqare root on both sides,
x= sqrt. 36
x= +- 6
Therefore x=+-6.