Part A: 3x + 15 = 5x - 25
Part B: x = 20
Answer:

Step-by-step explanation:
the quadratic function should be as follows:

Now let's confirm that the zeros of the function are 0 and 8

Therefore we can see that if x = 0

the equation is fulfilled
And we also have 
for this expresion to be equal to zero:

thus, if x = 8

the equation is also fulfilled
The zeros of the quadratic function
are 0 and 8.
3. 5x5x5. i am not sure if i am correct but i am assuming it is that.
Answer:
36
Step-by-step explanation:
a² + b² = c²
a² + 77² = 85²
a² + 5929 = 7225
a² = 1296
a = 36