If you mean this:

then x = 0. The property in play here is the following: Any number raised to the "0" power is equal to "1". In this case, we would need to set the exponent of 3x = 0 and solve for x...
If you mean the equation:

then to solve for x(your blank), simply divide both sides of the equation by

:
You would have x =

this can also be written as
Answer:
y = x + 7
Step-by-step explanation:
3y - 3x = 21
3y/3 - 3x/3 = 21/3
y = x + 7
Answer:
(-5,-2)
Step-by-step explanation:
because the point is 5 to the left of the origin and 2 down from the origin
Answer: f²+g²=h²
Step-by-step explanation:
In a right triangle, you use the Pythagorean Theorem: a²+b²=c² to find the hypotenuse of the triangle. I would believe that you could just substitute the variables in this equation with the ones that you have. This should show the relationship between the 3 unknown lengths of the sides.