Treat x^4 as the square of p: x^4 = p^2.
Then x^4 - 5x^2 - 36 = 0 becomes p^2 - 5p - 36 = 0.
This factors nicely, to (p-9)(p+4) = 0. Then p = 9 and p = -4.
Equating 9 and x^2, we find that x=3 or x=-3.
Equating -4 and x^2, we see that there's no real solution.
Show that both x=3 and x=-3 are real roots of x^4 - 5x^2 - 36 = 0.
Answer:
It is C. and btw........... DON'T TRUST LINKS!!
Answer:
The volume of the triangular prism is 
Step-by-step explanation:
we know that
The volume of the triangular prism is equal to

where
B is the area of the triangular face
L is the length of the prism
step 1
Find the area of the triangular face
The area of a triangle is equal to

we have

substitute

step 2
Find the volume
we have


substitute in the formula of volume


Do you have a photo, what tells us that the unknown number is multiplied by 3?