The only way to solve if it is equal to something
assuming that the teacher wanted you to make it equal to zero do
0=-3x^2-21x-54
remember if we can do
xy=0 then assume x and y=0
so factor
0=-3x^2-21x-54
undistribute the -3
0=-3(x^2+7x+18)
remember 0 times anything=0 so
x^2+7x+18 must equal zero
use quadratice formula which is
if you have
ax^2+bx+c=0 then
x=

x^2+7x+18
a=1
b=7
c=18
x=

x=

x=

i=√-1
x=

the zerose would be
x=

or
The answer is 8
Here's why:

The exponents are subtracted one from another when divided.

We can look at the problem this way:

Since we have the power of -1 on the 3, we apply this rule:

Also this rule because we have the power of 1 on the 6:

Then we get this:

We apply the rule:

We get this:
Answer:
Therefore, the original price of the hat is 22.5$.
4x+19=7x+16
4x=7x-3
-3x=3
x=1